Car-trains

Car-trains are a possible key advance in transportation technology. They have the potential to alleviate congestion by increasing throughput (number of vehicles per lane per hour) by a factor of at least two. Vehicles that are physically coupled or able to follow with a gap of less than 1 foot can reduce aerodynamic drag more than 50% (see graph and image). However, significant development issues regarding the controllability, safety and new driver behavior remain to be resolved.

From windtunnel tests of Chevy Lumina APVs in "The Aerodynamic Performance of Platoons: Final Report, by Zabat, Stabile, Frascaroll, Browand, California PATH Research Report 10/1995, ISSN 1055–1425.