Pure electric vehicles are an attractive solution to the problems of pollution and dwindling supply of oil. However, they will fulfill only a fraction of the transportation needs of people and businesses for the foreseeable future because of their limited range. Expensive batteries and long charging times also limit their appeal.
These limitations can be overcome if vehicles could draw power from a conductor embedded in the roadway. The conductor will provide power for moving the vehicle as well as keep its batteries charged. Relatively inexpensive batteries can be used since they would only be needed for local trips and to reach a powered highway.
One lane of a “powered highway” have would have a segmented conductor embedded in the road surface. The conductor segments would normally be unpowered. An approaching vehicle will activate the segments. The vehicle would be fitted with special tires, which will include a conducting ring. This ring would make contact with the conductor embedded in the road surface to draw power from it. The segments would be activated by a separate transmission line running along the highway but isolated from the road for safety reasons.
The powered highway concept not only overcomes the limitations of pure electric vehicles, it can potentially control vehicles using the roadway conductor to send and receive information from the vehicle. This opens up the possibility of vehicles being automatically controlled for relaxed long distance travel.
Powered highways are a better solution to the range limitations of electric vehicles than a network of battery swap stations. Even with foreseeable improvements in battery technology, the range of typical car would be around 50 miles. Thus a network of battery swapping stations would need to be approximately sixteen times denser than a the current gasoline filling stations since the range of a typical gasoline powered vehicle is four times larger (~200 miles).
Even the initially small sections of powered highways would be immediately useful and they can be gradually expanded to cover most of the interstate network. The powered lane does not have to provide a conductor continuously. It can be limited to sections, which are easy to access and maintain. Thus, bridges, tunnels, interchanges, etc. need not have a powered lane, since they represent a very small fraction of the time that a vehicle spends on a highway. During these short periods the vehicle will switch to it’s batteries for power.
There is potentially a huge market for manufacturing equipment for powered highways, the transmission lines, the tires and other equipment. As powered highways are turned into “smart” highways, there will be another market for control hardware and software.
No new technologies are needed to manufacture the conductor segments. High voltage power switching is also a well, established technology. Existing battery technologies are more than adequate to power electric vehicles for a few tens of miles.
Powered highways thus offer a gradual path to transition away from gasoline based transportation to non-polluting, smart, relaxed transportation for any sized vehicles.