Filling up the Roads
A single lane can safely handle 1700 vehicles per hour, using a 2 second following distance. On some city freeways single lanes carry up to 2700 vehicles per hour, due to traffic constantly blending into the mainstream. Following distances are drastically reduced, and multiple car pileups are a feature of this style of driving.
The minimum following distance between vehicles is necessary to allow the driver time to assimilate, react, and act, in time to avoid an accident. This is true of any vehicle unit. Because of this spacing, trains can move more people than buses which can move more people than cars in any given period of time.
If one were to group several cars together and control them as a unit, a dramatic improvement could be made in road capacity. For example, if 20 small cars were coupled together, and groups were separated with a 2 second gap, a single lane could carry 12000 vehicles per hour. This is the equivalent of building 5 to 6 additional highway lanes, going in the same direction. Follow the link to a simple animation of a highway traffic scenario comparing FlexiTrain with normal traffic flow.
If one of the vehicles in the group were to supply most of the energy for the trip, the biggest failing of current electric vehicles would be overcome: that of limited range.