What might driving on an automated highway be like The answer depends on what kind of system is ultimately adopted. Two distinct types are on the drawing board. The first is a special purpose lane system, in which certain lanes are reserved for automated vehicles. The second is a mixed traffic system: fully automated vehicles would share the road with partially automated or manually driven cars. A special-purpose lane system would require more extensive physical modifications to existing highways, but it promises the greatest gains in freeway (高速公路) capacity.
Under either scheme, the driver would specify the desired destination, furnishing this information to a computer in the car at the beginning of the trip or perhaps just before reaching the automated highway. If a mixed traffic system was in place, automated driving could begin whenever the driver was on suitably equipped roads. If special-purpose lanes were available, the car could enter them and join existing traffi
A. are being planned
B. are being modified
C. are now in wide use
D. are under construction