National Geographic : 1969 Sep
(Continuedfrom page 305) with guideways. In some systems, the car's power comes from an electric transmission line built into the road. In others, vehicles would simply be carried on a high-speed con veyor, or perhaps in a container. Computer ized guidance systems vary, too. "Before the first mile of automated high way is installed," Dr. Hafstad pointed out, "everyone will have to agree on just which system is to be used." Electric Cars Could Solve Smog Problem In looking at the problem of air pollution, Dr. Hafstad foresees the day when as-yet undeveloped batteries will make electric vehicles feasible. Engineers are striving to reduce the pollutant emission of today's en gines-but they expect the number of auto mobiles to double within two decades. Turbine engines, which burn fuel more efficiently than do piston engines, may be an interim step. "But right now," Dr. Hafstad commented, "turbine technology is very young, while our conventional engines are very advanced. It will take years for the turbines to catch up." Electric cars are on the market today, but the driving range between battery charges is limited to 50 miles or less. Some auto firms are experimenting with hybrid electric vehi cles, which use battery-powered motors in town and low-pollutant gasoline engines on the highway (page 338). Scientists are also working hard to improve batteries. One answer may be a variation of 310 the fuel cell that powers equipment aboard space capsules. The fuel cell-unlike ordinary batteries, which just store electrical energy -c onverts fuel directly into electricity. Almost surely the day will come when we will drive electric cars on our way into the city. Will we drive into even more night marish traffic tangles on city streets? I found a tantalizing bit of the answer near Stockholm, Sweden, last summer, as I strolled across a fountain-dotted plaza lined with attractive shops. No noisy traffic intruded here; this was a "walking plaza." At its perim eter, beyond the stores, high-rise apartment buildings stood like sentinels guarding it from the outside world. It was a peaceful "people place," and the key to its success was a network of tunnels beneath it. Down there, trucks were supply ing the stores with merchandise, and a sub way ferried people back and forth from nearby Stockholm. Roads Beneath Surface Defy the Weather Underground highways? Most transporta tion experts I've talked to don't consider them extravagant at all. Byron A. Bledsoe, princi pal engineer of the Highway Research Board in Washington, D. C., pointed out to me that transportation is basically a utility, like sew age, electricity, and telephone service. "Open sewers have gone underground," he said. "Electric lines and telephone lines are doing so now. In the future, surface roads especially the ones in downtown areas-may disappear too, leaving the surface for people."