Transport and mobility

A small prize. Letters shot between towns arrive sooner, which is a convenience now that most messages need no paper.

Who is paid. I assume the public post pays for it, and the engineering firms that already build for the post collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A lighter-than-air craft is slow and carries little beside aircraft and trains, so it stays a niche; this one runs to a timetable for the public.

Who is paid. The carrier or fleet operator that runs the airship line buys it and charges riders, and any workshop could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A home that drives itself from town to town suits travellers and holidaymakers, which is a modest trade.

Who is paid. Owners buy it, and it is easy to copy, so the vehicle makers that already have factories and dealers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Fast and pleasant travel under the sea is an outing or a ferry on a few routes, since most people have no need to go beneath the surface.

Who is paid. Passengers pay fares, and I assume once such a vessel works any shipyard could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Being fired across a river is a stunt where a bridge or boat would do.

Who is paid. I assume a ferry operator would run it, and a launcher of this kind is simple to copy, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. It is a desperate act by a crew, not a product anyone would buy.

Who is paid. Nothing is made or sold here, so nobody pays and no seller keeps anything.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Breathing gear for roaming the sea floor opened diving for sport, salvage and science, which is a real but modest trade.

Who is paid. I assume sport divers are the main buyers, and many firms can make tanks and valves, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A submarine that stays under for long periods and feeds itself is worth a great deal to a navy and an industry to those who build it.

Who is paid. I assume navies are the main buyers, and the shipyards that already hold naval contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. Sending things instantly across any distance would replace most shipping and haulage, which changes how most people are supplied and how most firms work.

Who is paid. Traders and carriers pay, since the description sends objects and not people, which is why the payer differs from the booths for travellers; once a firm had built it others could, so the carriers and builders that already own the depots and the customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A craft that needs no runway can reach rooftops, ships and wild country, which is worth an industry of its own.

Who is paid. Rescue services, armies and offshore firms buy it, and the established aircraft builders collect because the design can be copied but the factories and safety approval cannot quickly be had.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Cars that run on electric motors change the fuel and upkeep costs of the whole car industry, though they make the same trips.

Who is paid. Drivers buy them, and electric motors and batteries can be had by any maker, so the firms with factories, dealers and brands collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Trains pushed along by magnets run fast and clean, which changes the cost of travel by rail.

Who is paid. Governments pay for a public way of this size, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A hull that rides above the water is faster on short crossings but costly on large ships, so it stays a niche.

Who is paid. Ferry operators buy it, and many boat yards can build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Saving the energy of a climb for the way down cuts fuel use a little, which is a feature.

Who is paid. Owners pay for it through the price of the vehicle, and the established vehicle makers fit it and collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Fast capsules in sealed tubes would rival trains and aircraft on their routes, which changes the cost of travel between cities; this one runs under the ocean.

Who is paid. Governments pay for a public way of this size, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A bicycle with a motor makes cheap personal travel easy for many people who would not pedal far, which is worth an industry of its own.

Who is paid. Riders buy it, and many small factories can bolt a motor and battery to a frame, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A lighter-than-air craft is slow and carries little beside aircraft and trains, so it stays a niche; legs let this one cross rough ground.

Who is paid. Operators buy it, and airships are simple enough for many builders to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Flying on muscle alone is a sport for the fit, not a way of getting about.

Who is paid. Hobbyists buy it, and any maker of light frames and wings could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Powered flight for passengers is an industry of its own that shrank the time between distant cities.

Who is paid. Airlines buy the machines, and since flight itself was quickly copied, the few builders with the factories and safety approval collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A street that carries its riders would replace buses and cars on its route, which changes the cost of getting about a city.

Who is paid. Governments pay for a public way of this size, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A private vehicle that flies its owner over the roads would be an industry of its own, though it mostly replaces trips people already make by car.

Who is paid. Owners buy it as they buy a car, and once it works many firms could build it, so the vehicle makers that already have factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A lone vehicle for road, water and air does each job worse than a craft built for it, so it suits a few buyers who want them all.

Who is paid. I assume wealthy owners buy it, and once it was built other makers could copy it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Hired flight across a city, working as promised, would be an industry of its own beside road cabs.

Who is paid. The carrier or fleet operator that runs the air cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Balancing on fewer wheels makes a vehicle narrower but does nothing an ordinary car cannot already do.

Who is paid. Drivers buy it, and a gyroscope is easy to copy, so the car makers that already own the factories and dealers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A tunnel under the ocean would link continents by land, which changes the cost of travel and trade between them.

Who is paid. Governments pay for a public way of this size, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Skates with motors are a toy and a way round town for a few riders.

Who is paid. People buy it for themselves, and many workshops could build it once it is shown to work, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Scheduled flights across a city for many passengers at once would be an industry of its own beside buses and trains.

Who is paid. The carrier or fleet operator that runs the air bus buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A lift without cables is a better lift, useful in very tall buildings but a part of the building and not a new industry.

Who is paid. Building owners pay for it, and the lift makers that already fit and service lifts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Free personal flight with no limit stated would be an industry of its own, replacing many trips now made by car.

Who is paid. Riders buy it for themselves, and a light craft like this could be built by many workshops once the trick is known, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. An aircraft that flies very fast with almost no limit on range would change the costs of long-distance flight.

Who is paid. Airlines and freight carriers buy the aeroplane, and it is judged as a craft, not as its power source, so the aircraft makers that already build and service fleets collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A little vehicle for indoors and the street helps people who find walking hard, and is a convenience for others.

Who is paid. Riders buy it, and many firms can make a small electric cart, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A rig that lets a person fly wherever they please, working as promised, would be an industry of its own as the motorbike is; the description gives no limit on range or weather, so I assume there is no such limit.

Who is paid. Riders buy it for themselves, and a light craft like this could be built by many workshops once the trick is known, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Hired flight across a city, working as promised, would be an industry of its own beside road cabs.

Who is paid. The carrier or fleet operator that runs the air cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A railway carried through the sky would cross rivers, hills and cities without land or tunnels, changing the cost of building lines.

Who is paid. Governments pay for railways on this scale, and the builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Flying goods between distant cities is an industry of its own that made fast long-distance delivery ordinary.

Who is paid. Freight carriers buy the aircraft, and since any large builder can make a cargo plane, the builders and carriers that already own the factories and fleets collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. The description gives only a different way of staying aloft, so I assume it does what other aircraft already do.

Who is paid. Airlines would buy it, and the established aircraft builders collect because a new lifting method can be copied once shown.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A flat panel that lifts and holds still in the air is a small flying raft, useful for odd jobs and short hops rather than everyday travel.

Who is paid. Riders buy it for themselves, and a light craft like this could be built by many workshops once the trick is known, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A clock that shows the hour of the ground below is a handy extra for crews and passengers.

Who is paid. Airlines buy it with the aircraft, and any instrument maker could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A lighter-than-air craft is slow and carries little beside aircraft and trains, so it stays a niche; this one is built for long exploring flights.

Who is paid. Operators buy it, and airships are simple enough for many builders to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A screen showing where many aircraft are is a needed tool for those who direct air traffic, and few buy it.

Who is paid. Governments run air traffic control and pay for it, and the electronics firms that already hold those contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Nets round the rim of a huge aircraft are a safety fitting.

Who is paid. The operator of the aircraft buys them, and netting is simple to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A plane that folds small enough to carry puts flight in private hands, and the description states no limit on where it can fly, so it is judged with the free personal flyers as an industry of its own.

Who is paid. Riders buy it for themselves, and a light craft like this could be built by many workshops once the trick is known, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Walking on air lets a person climb without stairs, which is a marvel and a convenience but moves nobody far.

Who is paid. People buy a pair for themselves, and once the trick is known any shoemaker could fit it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A private vehicle that flies its owner over the roads would be an industry of its own, though it mostly replaces trips people already make by car.

Who is paid. Owners buy it as they buy a car, and once it works many firms could build it, so the vehicle makers that already have factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. An aircraft that flies on sunlight alone needs no fuel, which changes the costs of flying; I assume it carries passengers and freight, unlike the pilotless sunlight scout judged small elsewhere, and I judge the promise though the real thing carries very little.

Who is paid. Airlines and other operators pay for it through the aircraft, and the established aircraft builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Wheels that roll any way make parking and turning easier, which is a convenience.

Who is paid. Owners pay for them through the price of the vehicle, and the tyre and vehicle makers that already have factories and dealers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. Sending things instantly across any distance would replace most shipping and haulage, which changes how most people are supplied and how most firms work; this one sends people too.

Who is paid. I assume carriers and traders pay to send people and goods through, and once a firm had built it others could, so the carriers and builders that already own the depots, the ports and the customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A vehicle on many legs can cross ground that stops wheels, which matters in a few rough places.

Who is paid. Firms and armies working on rough ground buy it, and once walking machines work many builders could make them, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. The belt built for stations and long halls turned out a convenience, but the story sets it against the fixed pavement as the way people get about a town, and a moving pavement in place of streets would change the cost of getting about a city.

Who is paid. I assume a town pays for it as a public way, as with the other moving streets, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Judged as a working way to travel and signal faster than light, it would found an industry of its own, though few people would ever make the trip.

Who is paid. Carriers and shipping firms buy the ships, as they do in the other star drive entries, and once the drive is known others could build it, so the established ship builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A private vehicle that flies its owner over the roads would be an industry of its own, though it mostly replaces trips people already make by car.

Who is paid. Owners buy it as they buy a car, and once it works many firms could build it, so the vehicle makers that already have factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. Sending things instantly across any distance would replace most shipping and haulage, which changes how most people are supplied and how most firms work.

Who is paid. Traders and carriers pay, since the description sends objects and not people, which is why the payer differs from the booths for travellers; once a firm had built it others could, so the carriers and builders that already own the depots and the customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Sending things instantly across any distance would replace most shipping and haulage, which changes how most people are supplied and how most firms work.

Who is paid. Traders and carriers pay, since the description sends objects and not people, which is why the payer differs from the booths for travellers; once a firm had built it others could, so the carriers and builders that already own the depots and the customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Fast capsules in sealed tubes would rival trains and aircraft on their routes, which changes the cost of travel between cities.

Who is paid. Governments pay for a public way of this size, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Crossing the world in a short arc through the edge of space would be an industry of its own beside the airlines.

Who is paid. The carrier or fleet operator that runs the rocket service buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A private aircraft used like a car for daily trips would be an industry of its own, though it mostly replaces trips people already make by car.

Who is paid. Owners buy it as they buy a car, and once it works many firms could build it, so the vehicle makers that already have factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A plain pavement is only named here against the moving kind, yet safe places to walk serve nearly everyone in a town.

Who is paid. Towns pay for pavements as public works, and though paving is easy to do, the road builders that already hold the towns' contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A car that needs no driver gives back the hours spent at the wheel and opens car travel to people who cannot drive, which is worth an industry of its own; the signal only calls the car to its owner.

Who is paid. Owners buy it, and since several firms can build a driving system once it is shown to work, the car makers that already own factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Sending things instantly across any distance would replace most shipping and haulage, which changes how most people are supplied and how most firms work; this one reaches other planets and sends people too.

Who is paid. I assume carriers and traders pay to send people and goods through, and once a firm had built it others could, so the carriers and builders that already own the depots, the ports and the customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Taking the driver out of road freight changes the costs of the whole haulage industry.

Who is paid. Haulage firms buy it, and since several firms can build a driving system once it is shown to work, the truck makers and hauliers that already own factories, fleets and customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A moving walkway between cities would replace trains and roads on its route, which would change the cost of travel there.

Who is paid. Governments pay for a public way of this size, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. An electric motor makes a boat quieter and cleaner but it does the same job as before.

Who is paid. Boat owners buy it, and any boatyard can fit an electric motor, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A pipe to every home that delivers goods would take over much of the work of shops and delivery vans in a city.

Who is paid. I assume the city pays for the pipes as it pays for water mains, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A small craft for hunting whales serves a trade that most countries have ended.

Who is paid. I assume whaling firms may still buy it somewhere, and many boat yards could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Fast capsules in sealed tubes would rival trains and aircraft on their routes, which changes the cost of travel between cities.

Who is paid. Governments pay for a public way of this size, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A ship that crosses the cosmos would found an industry of its own, and I have not counted the travel through time, whose worth I cannot judge.

Who is paid. I assume governments would pay for and closely hold a craft that can also move through time, and the established space contractors that build for them collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A fall through the Moon would be a quick way between its far sides for the few people living there.

Who is paid. A government pays for a boring of this size, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A rotor craft that flies on sunlight alone needs no fuel, which changes the costs of flying; I assume it carries people and loads, unlike the pilotless sunlight scout judged small elsewhere, and I judge the promise.

Who is paid. Airlines and other operators pay for it through the aircraft, and the established aircraft builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Sending things instantly across any distance would replace most shipping and haulage, which changes how most people are supplied and how most firms work.

Who is paid. Traders and carriers pay, since the description sends objects and not people, which is why the payer differs from the booths for travellers; once a firm had built it others could, so the carriers and builders that already own the depots and the customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A private vehicle that flies its owner over the roads would be an industry of its own, though it mostly replaces trips people already make by car.

Who is paid. Owners buy it as they buy a car, and once it works many firms could build it, so the vehicle makers that already have factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A car that parks itself after dropping its rider saves a walk and some time, which is a convenience.

Who is paid. Drivers pay for it as a feature of the car, and the car makers that already sell the vehicles collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Reaching other stars in a useful time would found an industry of its own, though few people would ever make the trip.

Who is paid. Carriers and shipping firms buy the ships, as they do in the other star drive entries, and once the drive is known others could build it, so the established ship builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A tailless shape that reaches very thin air is a better kind of aircraft for a few tasks, not a new service.

Who is paid. I assume air forces are the main buyers of very high flyers, and the aircraft builders that already hold those contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Sensors that brake and steer for the driver make a car safer, which is a feature rather than a new way to travel.

Who is paid. Drivers pay for it with the car, and the car makers and their parts suppliers collect because the sensors are easy to copy.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Reaching other stars in a useful time would found an industry of its own, though few people would ever make the trip.

Who is paid. Carriers and shipping firms buy the ships, as they do in the other star drive entries, and once the drive is known others could build it, so the established ship builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Flying far above ordinary airliners is faster and smoother, which is a better aircraft and not a new industry.

Who is paid. Airlines and other operators pay for it through the aircraft, and the established aircraft builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Hauling goods with no crew aboard changes the costs of a whole freight industry.

Who is paid. Freight carriers buy it, and since the self-steering gear can be copied, the carriers and builders that already own the fleets and routes collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Paying road charges without stopping saves drivers a little time and the road owner some staff.

Who is paid. I assume road authorities buy the collection system, and the suppliers that already equip their roads collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A car that needs no driver gives back the hours spent at the wheel and opens car travel to people who cannot drive, which is worth an industry of its own.

Who is paid. Owners buy it, and since several firms can build a driving system once it is shown to work, the car makers that already own factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A cab with no driver takes the largest cost out of every taxi ride, which is worth an industry of its own.

Who is paid. The carrier or fleet operator that runs the cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Cancelling gravity would make lifting and moving heavy things far cheaper, which changes the costs of transport and building rather than meeting a basic need.

Who is paid. Firms that move and lift things buy it, and once it is built others could copy it, so the vehicle and aircraft makers that already own factories and customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A car that needs no driver gives back the hours spent at the wheel and opens car travel to people who cannot drive, which is worth an industry of its own.

Who is paid. Owners buy it, and since several firms can build a driving system once it is shown to work, the car makers that already own factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Crossing between continents in a short high arc would be an industry of its own beside the airlines.

Who is paid. The carrier or fleet operator that runs the rocket service buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A record of where the owner has been is a handy extra for travellers.

Who is paid. Travellers buy it, and any maker of small electronics could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A ferry across the lunar surface serves only the few people who are on the Moon.

Who is paid. Operators of lunar bases buy it, and any builder of space vehicles could make it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. The ordinary wheeled car changed where most people live, work and shop.

Who is paid. Drivers buy it, and since any firm can design a car, the makers with the factories, dealers and brands collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Knowing where an aircraft is matters to every flight, but it is an instrument inside the aircraft and not an industry by itself.

Who is paid. Airlines pay for it through the aircraft, and the instrument makers that already supply the aircraft builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Flying high above the weather is faster and smoother, which is a better aircraft and not a new industry.

Who is paid. Airlines and other operators pay for it through the aircraft, and the established aircraft builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. It is a wild animal of another world, not a technology anyone builds.

Who is paid. Nothing is made or sold here, so nobody pays and no seller keeps anything.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Riding on a cushion of air suits marsh, shallows and ice but is noisier and thirstier than wheels elsewhere, so it stays a niche.

Who is paid. This one is a compact personal craft, so riders buy it for themselves, and many builders can make an air cushion craft, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A small hovering craft for watching a sport from above serves only a few officials.

Who is paid. Sports bodies buy it, and many builders can make a small hovering craft, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Cushions on the outside of a car soften a crash, which is a safety feature.

Who is paid. Owners pay for it through the price of the vehicle, and the established vehicle makers fit it and collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A road that does the driving would give every car on it the gains of driverless travel, but only where such roads are built.

Who is paid. Governments pay for roads, and the control gear is not hard to copy, so the road builders and signalling suppliers that already hold public works contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. This is an agreed set of routes for ships rather than a thing anyone makes or buys.

Who is paid. Nothing is made or sold here, so nobody pays and no seller keeps anything.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A compact nuclear engine would free vehicles from fuel stops and change the running costs of transport.

Who is paid. Vehicle and ship builders buy it, but only the few firms a government trusts with nuclear fuel could make it, so those permit holders keep the gain.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Padding that protects fragile cargo from jolts is useful packing and nothing more.

Who is paid. Shippers buy it, and padded containers are simple for any firm to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A moving desk for looking things up is a convenience for a few kinds of work.

Who is paid. Firms buy it for their staff, and any vehicle fitter could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A clear roof gives a view of the sky, which is a comfort.

Who is paid. Owners pay for it through the price of the vehicle, and the established vehicle makers fit it and collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. The description promises only short hops, so it is a sport and a convenience rather than a way most people would travel.

Who is paid. Riders buy it for themselves, and a light craft like this could be built by many workshops once the trick is known, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Free personal flight with no limit stated would be an industry of its own, replacing many trips now made by car.

Who is paid. Riders buy it for themselves, and a light craft like this could be built by many workshops once the trick is known, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Moving pavements that carry crowds over long distances would replace trains and roads on their routes, which would change the cost of travel there.

Who is paid. Governments pay for a public way of this size, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. An armoured vehicle that crosses almost any ground is worth having for an army or an expedition, and few are needed.

Who is paid. I assume armies are the main buyers, and the firms that already hold army supply contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. Crowded air lanes are a nuisance that comes with personal aircraft, not a thing anyone would buy.

Who is paid. Nothing is sold, so there is no buyer and no seller.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A narrow self-balancing vehicle is a handy way round town but does little that a small car or motorbike does not.

Who is paid. Owners buy it as they buy a car, and once it works many firms could build it, so the vehicle makers that already have factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A narrow self-balancing vehicle is a handy way round town but does little that a small car or motorbike does not.

Who is paid. Owners buy it as they buy a car, and once it works many firms could build it, so the vehicle makers that already have factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A flapping aircraft for the thin air of another planet serves only the few people living there.

Who is paid. Settlements and their suppliers buy it, and any aircraft workshop there could copy it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. It is a road car with short hops over water and through the air added, which is a thrill more than a new way to travel.

Who is paid. Drivers buy it, and since it only leaps briefly rather than flies, it is an ordinary car feature that the makers with factories and dealers collect on.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A road that does the driving would give every car on it the gains of driverless travel, but only where such roads are built.

Who is paid. Governments pay for roads, and the control gear is not hard to copy, so the road builders and signalling suppliers that already hold public works contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. The description promises only short hops, so it is a sport and a convenience rather than a way most people would travel.

Who is paid. Riders buy it for themselves, and a light craft like this could be built by many workshops once the trick is known, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. The walkway built in airports and large buildings turned out a convenience, but the story promises moving pavements in place of city streets, and that would replace buses and cars on their routes and change the cost of getting about a city.

Who is paid. I assume a town pays for it as a public way, as with the other moving streets, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A car that runs on sunlight alone needs no fuel or charging, which changes the cost of driving; the real thing gathers far less than the promise, and I judge the promise, as with the vehicle sun panels judged under energy.

Who is paid. Owners buy it as they buy a car, and once it works many firms could build it, so the vehicle makers that already have factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A gauge that speaks its reading is a small extra for drivers.

Who is paid. Drivers pay for it with the car, and it is simple to make and fit, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Cancelling gravity would make lifting and moving heavy things far cheaper, which changes the costs of transport and building rather than meeting a basic need.

Who is paid. Firms that move and lift things buy it, and once it is built others could copy it, so the vehicle and aircraft makers that already own factories and customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. The description calls it a pavement, so it is judged as a moving street and not as the walkway found in large buildings, and a street that carries its walkers would change the cost of getting about a city.

Who is paid. I assume a town pays for it as a public way, as with the other moving streets, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Balancing upright on a lone rail makes the line cheaper to lay but carries people as trains already do.

Who is paid. I assume this one runs on a rail as public transport, so a city government pays, and the established railway builders collect because a gyroscope is easy to copy.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A bus with no driver to pay makes bus travel cheaper and more frequent, which would be an industry of its own.

Who is paid. The carrier or fleet operator that runs the bus buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Hired flight across a city, working as promised, would be an industry of its own beside road cabs.

Who is paid. The carrier or fleet operator that runs the air cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Riding on a cushion of lift suits marsh, shallows and ice but is noisier and thirstier than wheels elsewhere, so it stays a niche.

Who is paid. Operators buy it, and many builders can make a cushion craft, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Hired flight across a city, working as promised, would be an industry of its own beside road cabs; the real rotor cab services stayed a costly niche.

Who is paid. The carrier or fleet operator that runs the air cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A sail craft on open sand is a sport and a way across a few deserts.

Who is paid. People buy it for themselves, and many workshops could build it once it is shown to work, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A rugged vehicle that pulls and carries over rough ground is a useful working machine among many like it.

Who is paid. Farms, mines and building firms buy it, and the established makers of heavy vehicles collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A narrow self-balancing vehicle is a handy way round town but does little that a small car or motorbike does not.

Who is paid. Owners buy it as they buy a car, and once it works many firms could build it, so the vehicle makers that already have factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A nimble light aircraft for hunting is a toy for the rich.

Who is paid. Wealthy sportsmen buy it, and many small builders can make a light aircraft, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A cab with no driver takes the largest cost out of every taxi ride, which is worth an industry of its own.

Who is paid. The carrier or fleet operator that runs the cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A pass that shows you are going the right way is a small help to travellers in a big station.

Who is paid. Transport operators would hand it out with the fare, and it is simple to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A powered chair for people raised in weak gravity serves a very small group.

Who is paid. Users buy it for themselves, and any maker of mobility chairs could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A walkway that reaches out to a docked ship is a convenience at ports.

Who is paid. Port operators buy it, and the firms that already build moving walkways and gangways collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A very large hauler lowers the cost of moving ore and earth at a few big sites.

Who is paid. Mining and building firms buy it, and the established makers of heavy vehicles collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A bore that takes each car straight to its stop would lift traffic off the streets, which changes the cost of getting about a city.

Who is paid. Governments pay for a public way of this size, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Letters shot straight into the house arrive sooner, which is a convenience now that most messages need no paper.

Who is paid. I assume the public post pays for the pipes, and the engineering firms that already build for the post collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A system that flies the aircraft changes the crew costs and the safety of the whole airline industry; the real thing still leaves pilots aboard, so the promise is larger than what was built.

Who is paid. Airlines and aircraft builders buy it, and the firms already trusted to supply flight controls collect because a newcomer cannot easily win safety approval.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A cabin hung in the air for the view is a sightseeing ride.

Who is paid. Tour operators buy it, and it is simple enough for many builders to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A pedal cycle for the Moon serves only the few people who are there.

Who is paid. I assume settlers buy it for themselves, and any cycle maker could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A sail car on a track goes only where the track runs and when the wind blows, so it suits a few places.

Who is paid. I assume a carrier runs the line, and the cars are simple enough for many builders to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A window that shows the land straight below is a treat for passengers.

Who is paid. Airlines pay for it through the aircraft, and the optics are simple to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. It does the work commuter trains already do, only more quietly.

Who is paid. City governments pay for commuter lines, and the established railway builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Selling passes without a clerk saves a transport operator some wages and saves travellers a queue.

Who is paid. Transport operators buy it, and many firms can build a vending kiosk, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A car that needs no driver gives back the hours spent at the wheel and opens car travel to people who cannot drive, which is worth an industry of its own.

Who is paid. Owners buy it, and since several firms can build a driving system once it is shown to work, the car makers that already own factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A bus with no driver takes the largest running cost out of public transport.

Who is paid. The carrier or fleet operator that runs the bus buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Cars that share what they see are a little safer and smoother, which is a helpful feature rather than a product on its own.

Who is paid. Car makers pay to fit it, and it only works if every maker uses the same shared signals, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Travel between stars faster than light would open trade and settlement on other worlds, which is an industry of its own.

Who is paid. I assume shipping lines and settlers pay, and once a ship of this kind flies others could be built, so the shipbuilders and carriers that already own yards, ports and fleets collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Trains that float on magnets run fast and clean, which changes the cost of travel by rail.

Who is paid. Governments pay for a public way of this size, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A hired car with no driver to pay makes cab rides far cheaper, which would be an industry of its own.

Who is paid. The carrier or fleet operator that runs the cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A car that needs no driver gives back the hours spent at the wheel and opens car travel to people who cannot drive, which is worth an industry of its own; cleaning itself is a small extra.

Who is paid. Owners buy it, and since several firms can build a driving system once it is shown to work, the car makers that already own factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. The name is only a label for the ordinary starship of its story, and ships that cross between stars slower than light would still open other worlds to settlement over long voyages, which is an industry of its own.

Who is paid. I assume shipping lines and settlers pay, and many yards could build such ships, so the shipbuilders and carriers that already own yards, ports and fleets collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A tree that grows boat hulls makes small boats cheaper, and small boats are a modest trade.

Who is paid. People buy the tree or its pods, and since living stock multiplies once any of it is sold, no originator can hold it, so the nurseries and boat dealers that already hold stock and yards collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A beam that both marks the route and pushes craft along would be a highway through space, changing the cost of space travel.

Who is paid. I assume a government builds a beam like this as a public work, and the space contractors that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A rig that lets a person fly wherever they please, working as promised, would be an industry of its own as the motorbike is; the description gives no limit on range or weather, so I assume there is no such limit.

Who is paid. Riders buy it for themselves, and a light craft like this could be built by many workshops once the trick is known, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A road that does the driving would give every car on it the gains of driverless travel, but only where such roads are built.

Who is paid. Governments pay for roads, and the control gear is not hard to copy, so the road builders and signalling suppliers that already hold public works contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A vehicle that bounds along on a lone leg suits rough ground where wheels fail, which is a niche.

Who is paid. Riders buy it, and many workshops could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Instant travel between any places would change where most people live and work and replace nearly all other transport.

Who is paid. The carriers that run the network buy the machines and charge travellers for each trip, and since nothing described stops a second builder, the firms that already own sites, power and travellers' custom collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A car for a lone rider is a cheaper, smaller car, which is a niche beside the ordinary car.

Who is paid. Owners buy it as they buy a car, and once it works many firms could build it, so the vehicle makers that already have factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Tunnels with shared vehicles under a city carry crowds past the traffic, which changes the cost of getting about a city.

Who is paid. Governments pay for a public way of this size, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A hired car with no driver to pay makes cab rides far cheaper, which would be an industry of its own.

Who is paid. The carrier or fleet operator that runs the cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Hired flight across a city, working as promised, would be an industry of its own beside road cabs.

Who is paid. The carrier or fleet operator that runs the air cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Taking the driver out of road freight changes the costs of the whole haulage industry.

Who is paid. Haulage firms buy it, and since several firms can build a driving system once it is shown to work, the truck makers and hauliers that already own factories, fleets and customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A vehicle on broad soft tyres for desert sand serves the few who work in such places.

Who is paid. Firms working in deserts buy it, and wide tyres are easy to copy, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A craft that flies people to work by itself would be an industry of its own, though it mostly replaces trips people already make by car.

Who is paid. I assume commuters own it as they own a car, and once it works many firms could build it, so the vehicle makers that already have factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Setting a flying car neatly into its space is a convenience for drivers.

Who is paid. I assume the owners of parking places fit the beams, and the firms that already equip such places collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A small car on a lone rail serves a few routes in a city.

Who is paid. I assume a city pays for the line, and the builders that already hold transit contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. I assume the distant places are other worlds, as in the story and the other gate entries, and cheap instant passage between worlds would open new land and trade to a large share of humanity.

Who is paid. I assume carriers and traders pay to send people and goods through, which is why the payer differs from the booths for travellers within a world, and once a gate is built others could build more, so the large builders and carriers that already own the ports and the customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A hired car with no driver to pay makes cab rides far cheaper, which would be an industry of its own.

Who is paid. The carrier or fleet operator that runs the cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. It moves people between floors as lifts and stairs already do, so the gain is a convenience.

Who is paid. Building owners buy it, and the firms that already fit and service lifts collect because the machine itself is easy to copy.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A couch that eases heavy acceleration is needed only by the few who travel by rocket.

Who is paid. Space carriers buy it, and it is padding and springs any supplier could make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Taking the driver out of road freight changes the costs of the whole haulage industry.

Who is paid. Haulage firms buy it, and since several firms can build a driving system once it is shown to work, the truck makers and hauliers that already own factories, fleets and customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A cleared place to arrive safely is useful only if people can teleport, and then it is a plain piece of floor.

Who is paid. Owners of buildings and public places provide it, and anyone can mark out a clear space, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A towed tube is a cheaper way to move oil by sea on a few routes.

Who is paid. Oil shippers buy it, and many makers of flexible tanks could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Fast capsules in sealed tubes would rival trains and aircraft on their routes, which changes the cost of travel between cities.

Who is paid. Governments pay for a public way of this size, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Judged only as a lift, it moves people between floors as lifts already do; control of gravity itself would be worth far more.

Who is paid. Building owners buy it, and the firms that already fit and service lifts collect because the machine itself is easy to copy.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Driving a cab from afar still needs a person for each cab, so it saves little.

Who is paid. The carrier or fleet operator that runs the cab buys it and charges riders, and any workshop could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A rugged small vehicle for other worlds serves only the few people who are there.

Who is paid. Operators of bases buy it, and any builder of space vehicles could make it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Flying by muscle power inside lunar caverns is a sport for the few people who live there.

Who is paid. People buy it for themselves, and many workshops could build it once it is shown to work, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A cab that flies over the streets with no pilot to pay would be an industry of its own beside cabs and buses.

Who is paid. The carrier or fleet operator that runs the air cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Balancing on fewer wheels makes a vehicle narrower but does nothing an ordinary car cannot already do.

Who is paid. Because this one hauls freight, haulage firms buy it, and a gyroscope is easy to copy, so the truck makers that already own the factories and dealers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A car that needs no driver gives back the hours spent at the wheel and opens car travel to people who cannot drive, which is worth an industry of its own; the sensor that follows road markings is the heart of such a car.

Who is paid. Owners buy it, and since several firms can build a driving system once it is shown to work, the car makers that already own factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A vehicle for crossing lunar dust serves only the few people who are on the Moon.

Who is paid. Operators of lunar bases and tours buy it, and any builder of space vehicles could make it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A vehicle for crossing lunar dust serves only the few people who are on the Moon.

Who is paid. Operators of lunar bases and tours buy it, and any builder of space vehicles could make it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A field that keeps everyone in a vehicle unhurt in any collision does far more than the cushions and bags beside it, which only soften a crash, and ending injury on the roads would change the costs of motoring, insurance and emergency care.

Who is paid. Owners pay for it through the price of the vehicle, and I assume that once the field is shown to work other firms could build it, so the established vehicle makers fit it and collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Sending things instantly across any distance would replace most shipping and haulage, which changes how most people are supplied and how most firms work; this one sends people too.

Who is paid. I assume carriers and traders pay to send people and goods through, and once a firm had built it others could, so the carriers and builders that already own the depots, the ports and the customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. It prevents some crashes, but it is a safety feature in a car rather than something people seek out.

Who is paid. Drivers pay for it with the car, often because the law requires it, and the car makers and their parts suppliers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. Cheap instant passage between worlds would open new land and trade to a large share of humanity; I assume the relay post holds the machine that passes travellers on, so it is judged as the gate and not as a building.

Who is paid. I assume carriers and traders pay to send people and goods through, and once a gate is built others could build more, so the large builders and carriers that already own the ports and the customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Cheap instant passage between worlds would open new land and trade to a large share of humanity.

Who is paid. I assume carriers and traders pay to send people and goods through, and once a gate is built others could build more, so the large builders and carriers that already own the ports and the customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A system that flies the aircraft changes the crew costs and the safety of the whole airline industry.

Who is paid. Airlines and aircraft builders buy it, and the firms already trusted to supply flight controls collect because a newcomer cannot easily win safety approval.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A very fast boat that skims the water is a thrill for those who can afford it.

Who is paid. Wealthy boat owners buy it, and many boatyards can build a fast boat, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. The description limits it to low hops, so it is a small craft for short trips.

Who is paid. Riders buy it for themselves, and a light craft like this could be built by many workshops once the trick is known, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A narrow self-balancing vehicle is a handy way round town but does little that a small car or motorbike does not.

Who is paid. The carrier or fleet operator that runs the scooters for hire buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. The description limits it to short surface trips, so it is a small runabout.

Who is paid. People buy it for themselves, and many workshops could build it once it is shown to work, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A cab with no driver takes the largest cost out of every taxi ride, which is worth an industry of its own.

Who is paid. The carrier or fleet operator that runs the cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A flying wing that lifts whole mining machines saves time at remote sites, which matters to a single trade.

Who is paid. Mining firms buy it, and the builders of heavy aircraft that already serve them collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Flapping wings give an aircraft more agile flight, but it does the work aircraft and rotor craft already do.

Who is paid. Airlines and other operators pay for it through the aircraft, and the established aircraft builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A compass that reads local magnetic quirks is a backup way to find position.

Who is paid. Ship and aircraft operators buy it, and any instrument maker could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Flapping wings give an aircraft more agile flight, but it does the work aircraft and rotor craft already do.

Who is paid. Airlines and other operators pay for it through the aircraft, and the established aircraft builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A car that needs no driver gives back the hours spent at the wheel and opens car travel to people who cannot drive, which is worth an industry of its own.

Who is paid. Owners buy it, and since several firms can build a driving system once it is shown to work, the car makers that already own factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Route guidance in the car saves wrong turns and time, which is a convenience.

Who is paid. Drivers pay for it with the car, and the car makers and the firms that already hold maps of every road collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A small craft that flies a few people low over the roads would be an industry of its own, though it mostly replaces trips people already make by car; I assume it is privately owned.

Who is paid. Owners buy it as they buy a car, and once it works many firms could build it, so the vehicle makers that already have factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A wheeled craft driven by sail is a sport and a way across a few open plains.

Who is paid. People buy it for themselves, and many workshops could build it once it is shown to work, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A seat lifted by trained birds is a novelty ride for a few people.

Who is paid. Riders pay for it, and anyone who can train the birds could offer it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A wagon drawn by a beast does what a truck or tractor does, so it is a curiosity.

Who is paid. I assume carters buy it, and anyone who can breed and feed the beast could sell it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Free personal flight with no limit stated would be an industry of its own, replacing many trips now made by car.

Who is paid. Riders buy it for themselves, and a light craft like this could be built by many workshops once the trick is known, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A rig that lets a person fly wherever they please, working as promised, would be an industry of its own as the motorbike is; the description gives no limit on range or weather, so I assume there is no such limit.

Who is paid. Riders buy it for themselves, and a light craft like this could be built by many workshops once the trick is known, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Balancing on fewer wheels makes a vehicle narrower but does nothing an ordinary car cannot already do.

Who is paid. Drivers buy it, and a gyroscope is easy to copy, so the car makers that already own the factories and dealers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. I assume passage through the gate is cheap and open to all as in the like entries, and instant passage between worlds would open new land and trade to a large share of humanity.

Who is paid. I assume carriers and traders pay to send people and goods through, and once a gate is built others could build more, so the large builders and carriers that already own the ports and the customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A lighter-than-air craft is slow and carries little beside aircraft and trains, so it stays a niche; this one carries commuters.

Who is paid. The carrier or fleet operator that runs the airship line buys it and charges riders, and any workshop could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Cheap instant passage between worlds would open new land and trade to a large share of humanity.

Who is paid. I assume carriers and traders pay to send people and goods through, and once a gate is built others could build more, so the large builders and carriers that already own the ports and the customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Cushions that save riders in a crash matter greatly to those riders, but they are a safety feature inside a vehicle, as the other safety features here are.

Who is paid. Drivers pay for them with the car, and the parts suppliers that already sell to the car makers collect because the design is easy to copy.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A flying motorbike that carries its rider wherever they please would be an industry of its own as the motorbike is; the kitchen and medical kit aboard add comfort rather than reach.

Who is paid. Riders buy it for themselves, and a light craft like this could be built by many workshops once the trick is known, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A motorbike that stores its energy in a spinning wheel is another way to power a bike, not a new use for it.

Who is paid. Riders buy it, and a flywheel is plain engineering many firms could copy, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A walking mount for a lone rider goes where wheels cannot, which is a niche beside cars and bikes.

Who is paid. People buy it for themselves, and many workshops could build it once it is shown to work, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Shaping the air round a flying vehicle gives a smoother, quieter flight, which is a feature.

Who is paid. Airlines and other operators pay for it through the aircraft, and the established aircraft builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A basic small land vehicle is a cheap runabout, which I take to be a niche beside the ordinary car.

Who is paid. Owners buy it as they buy a car, and once it works many firms could build it, so the vehicle makers that already have factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Instant travel from place to place would end most journeys by road, rail and air and change where most people live and work.

Who is paid. The carriers that run the network buy the machines and charge travellers for each trip, and since nothing described stops a second builder, the firms that already own sites, power and travellers' custom collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Instant travel from place to place would end most journeys by road, rail and air and change where most people live and work.

Who is paid. The carriers that run the network buy the machines and charge travellers for each trip, and since nothing described stops a second builder, the firms that already own sites, power and travellers' custom collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Instant travel between any places would change where most people live and work and replace nearly all other transport.

Who is paid. The carriers that run the network buy the machines and charge travellers for each trip, and since nothing described stops a second builder, the firms that already own sites, power and travellers' custom collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Flying on muscle alone is a sport for the fit, not a way of getting about.

Who is paid. Hobbyists buy it, and any maker of light frames and wings could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. An ordinary ground vehicle, judged as the motor car, changed where most people live, work and shop.

Who is paid. Drivers buy it, and since any firm can design a car, the makers with the factories, dealers and brands collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. I assume the ships that use these natural shortcuts are what is sold, and reaching other stars would found an industry of its own, though few would make the trip.

Who is paid. Carriers and shipping firms buy the ships, as they do in the other star drive entries, and once the drive is known others could build it, so the established ship builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. A fixed route between stars is a feature of space in the story and not something built or sold.

Who is paid. Nothing is sold, so there is no buyer and no seller.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A car that needs no driver gives back the hours spent at the wheel and opens car travel to people who cannot drive, which is worth an industry of its own.

Who is paid. Owners buy it, and since several firms can build a driving system once it is shown to work, the car makers that already own factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A car that needs no driver gives back the hours spent at the wheel and is worth an industry of its own; hovering above the road adds little to that.

Who is paid. Owners buy it, and since several firms can build a driving system once it is shown to work, the car makers that already own factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Trained fish that tow floating houses serve only people who live on the water.

Who is paid. Houseboat dwellers buy or hire them, and anyone who can train the fish can sell them, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Trains that fall through deep tunnels would cross long distances fast on little fuel, changing the costs of long-distance travel.

Who is paid. Governments pay for tunnels on this scale, and the tunnelling and railway builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. The description gives a hovering car held to flat ground and names no cancelling of gravity, so I judge it with the cushion craft as a niche beside the ordinary car.

Who is paid. Owners buy it for themselves, and many builders can make a craft that hovers low over flat ground, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A giant roving home for desert plains suits a few people who live and work there.

Who is paid. I assume the people who live in it buy it, and any maker of heavy tracked vehicles could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A lighter-than-air craft is slow and carries little beside aircraft and trains, so it stays a niche; adding wings helps it carry more.

Who is paid. Operators buy it, and airships are simple enough for many builders to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Machinery that stores and fetches cars fits more of them into a garage, which is a saving for the owner of the garage.

Who is paid. Garage owners buy it, and it is ordinary machinery many firms can build, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Trains that fall through deep tunnels would cross long distances fast on little fuel, changing the costs of long-distance travel.

Who is paid. Governments pay for tunnels on this scale, and the tunnelling and railway builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A private vehicle that flies its owner over the roads would be an industry of its own, though it mostly replaces trips people already make by car.

Who is paid. I assume the warriors buy their own craft as others buy a car, and the weapons do not make it harder to copy, so the vehicle makers that already have factories and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A small car steered by a bar is a compact car, which is a niche beside the ordinary car.

Who is paid. Owners buy it as they buy a car, and once it works many firms could build it, so the vehicle makers that already have factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Free personal flight with no limit stated would be an industry of its own, replacing many trips now made by car.

Who is paid. Riders buy it for themselves, and a light craft like this could be built by many workshops once the trick is known, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Fast capsules in sealed tubes would rival trains and aircraft on their routes, which changes the cost of travel between cities.

Who is paid. Governments pay for a public way of this size, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Judged as the flying car of the story's city, which would be an industry of its own; the police craft described is only one use of it.

Who is paid. This one is a police craft, so the government pays, and the vehicle makers that already hold police fleet contracts collect because the craft can be copied.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Instant travel from place to place would end most journeys by road, rail and air and change where most people live and work.

Who is paid. The carriers that run the network buy the machines and charge travellers for each trip, and since nothing described stops a second builder, the firms that already own sites, power and travellers' custom collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A hired car with no driver to pay makes cab rides far cheaper, which would be an industry of its own.

Who is paid. The carrier or fleet operator that runs the cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Crossing the world in a short arc above the air would be an industry of its own beside the airlines.

Who is paid. The carrier or fleet operator that runs the rocket service buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Flying on muscle alone is a sport, and these wings work only where gravity is weak, so very few people could ever use them.

Who is paid. Hobbyists buy it, and any maker of light frames and wings could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Engine noise for a quiet vehicle is a small matter of taste or of warning people on foot.

Who is paid. Drivers pay for it, and a recording and a speaker can be made by anyone, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A train that needs no track saves the cost of laying it, but it is then close to a road convoy, so the gain is modest.

Who is paid. Hauliers and carriers buy it, and the established makers of heavy vehicles collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Silence would let helicopters work in places that now refuse them, but they would still be costly to fly, so I judge it a better helicopter rather than a new industry.

Who is paid. Operators and police forces buy it, and the established helicopter builders collect once the quieting method is known.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Roads that steer the cars on them would cut crashes and jams, which changes the cost of road travel.

Who is paid. Governments pay for the roads, and the builders and electronics firms that already hold road contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A walking vehicle for a lone rider goes where wheels cannot, which is a niche beside cars and bikes.

Who is paid. People buy it for themselves, and many workshops could build it once it is shown to work, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Hired flight across a city, working as promised, would be an industry of its own beside road cabs.

Who is paid. The carrier or fleet operator that runs the air cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Riding on a cushion of air suits marsh, shallows and ice but is noisier and thirstier than wheels elsewhere, so it stays a niche.

Who is paid. Ferry and hire operators buy it, and many builders can make an air cushion craft, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A seated ride on a fixed outdoor route serves a few districts, airports and fairgrounds.

Who is paid. I assume a city or public body pays for the line, and the builders that already hold transit contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. Cheap instant passage between worlds would open new land and trade to a large share of humanity.

Who is paid. I assume carriers and traders pay to send people and goods through, and once a gate is built others could build more, so the large builders and carriers that already own the ports and the customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A flying carpet that carries its rider wherever they please, working as promised, would be an industry of its own as the motorbike is; the description gives no limit on range or weather, so I assume there is no such limit.

Who is paid. Riders buy it for themselves, and a light craft like this could be built by many workshops once the trick is known, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A living animal bred to carry riders does a car's job more slowly, so I judge it a curiosity.

Who is paid. People buy it as they would a car, and since living stock multiplies once any of it is sold, no originator can hold it, so the breeders and vehicle dealers that already hold stock, workshops and showrooms collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A rescue aircraft held up by spinning cylinders is another way to do what rescue aircraft already do.

Who is paid. Hospitals and rescue services buy it, and the established aircraft builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A car that is grown and not built is a curiosity beside the ordinary car unless it is much cheaper, which the description does not say.

Who is paid. People buy it as they would a car, and since living stock multiplies once any of it is sold, no originator can hold it, so the breeders and vehicle dealers that already hold stock, workshops and showrooms collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A fast armoured car for rushing food to the door is a costly way to do a job a scooter does.

Who is paid. Delivery firms buy it, and it is an ordinary car made faster and tougher, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Riding on a cushion of air suits marsh, shallows and ice but is noisier and thirstier than wheels elsewhere, so it stays a niche.

Who is paid. The carrier or fleet operator that runs the hire car buys it and charges riders, and any workshop could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A tow from a passing car is a trick for a few daring riders.

Who is paid. Riders buy it, and a magnet on a line is simple to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Wheels that smooth out rough ground are a comfort on bad roads.

Who is paid. Operators of vehicles on rough ground buy them, and many wheel makers could build them, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A smoother ride is a comfort for passengers and saves a little wear, which is a convenience.

Who is paid. Airlines pay for it through the aircraft, and the established aircraft builders fit it and collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. It moves people between floors as lifts and stairs already do, so the gain is a convenience.

Who is paid. Building owners buy it, and the firms that already fit and service lifts collect because the machine itself is easy to copy.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Route guidance in the car is a convenience, and a screen that bends and pops out adds only a little to it.

Who is paid. Drivers pay for it with the car, and the car makers and the firms that already hold maps of every road collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Legs that feel the ground carry a vehicle over rough country, which is a niche.

Who is paid. Operators buy it for their work, and many builders could make it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A robot horse for a lone rider is a pleasure mount and a way across rough ground, not everyday transport.

Who is paid. Riders buy it, and once walking machines work many firms could build them, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A motorbike that keeps itself upright is a safer motorbike, which is a feature.

Who is paid. Owners pay for it through the price of the vehicle, and the established vehicle makers fit it and collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A sealed mask for very deep diving serves the few who work far below the surface.

Who is paid. Deep sea operators buy it, and it is specialist kit several suppliers could make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A hard shell makes an airship tougher, but airships remain a niche for slow heavy loads and sightseeing.

Who is paid. Cargo and tour operators buy it, and a rigid shell is not hard to copy, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A lift to the sea floor serves the few places where people work or holiday under the sea.

Who is paid. Undersea operators buy it, and the marine engineering firms that already build for them collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A road that does the driving would give every car on it the gains of driverless travel, but only where such roads are built.

Who is paid. Governments pay for roads, and the control gear is not hard to copy, so the road builders and signalling suppliers that already hold public works contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Putting a whole city on wheels gains its people little beyond the power to move on, at great cost.

Who is paid. I assume the city itself pays, and the large engineering firms that already build for cities collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. A hall where captured towns are broken up is a place in the story and not a thing anyone would buy.

Who is paid. Nothing is sold, so there is no buyer and no seller.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A train that lays its own track ahead saves the work of building the line first, which helps on a few new routes.

Who is paid. Railway builders buy it, and the established makers of railway machines collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A cab with no driver takes the largest cost out of every taxi ride, which is worth an industry of its own.

Who is paid. The carrier or fleet operator that runs the cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Punishing drivers who dodge the rules keeps traffic in order, which is a tool for the police.

Who is paid. Governments pay for road enforcement, and the firms that already supply road and police equipment collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Stopping a fleeing car from a distance makes chases safer, which serves police forces alone.

Who is paid. Police forces pay for it, and the firms that already supply police gear and car electronics collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Driving an ordinary car from afar still needs a person for each car, so it saves little and suits a few special jobs.

Who is paid. Fleet owners buy it, and remote controls are easy to fit to any car, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A plate that can change what it shows is a small convenience for lawful owners and mostly a help to those dodging the law.

Who is paid. Car owners buy it, and I assume it is sold freely as in the story, where any maker of small screens could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Keeping goods in parked cars near buyers would speed some deliveries, but shops and depots already sit close to most people.

Who is paid. Retailers pay for it, and the delivery firms that already run the networks and hold the customers collect because the idea is easy to copy.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Hauling goods with no crew aboard changes the costs of a whole freight industry.

Who is paid. Freight carriers buy it, and since the self-steering gear can be copied, the carriers and builders that already own the fleets and routes collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.