Most trips in U.S. metropolitan regions are driven alone, which is costly to individuals and society and leads to congestion and air pollution. A shared-use system aims to reduce traffic by reducing the number of cars needed by households and encouraging commuters to walk, bike, and use transit, at least for part of their trips. For commuters especially, shared-use vehicles could offer a low-cost, low-hassle alternative to private vehicles. Furthermore, carsharing should help air quality by incorporating low-emission vehicles into shared-use fleets.

The CarLink field test combined short-term rental vehicles with communication and reservation technologies to facilitate shared-vehicle access. The ten-month demonstration was implemented and researched by two teams at the Institute of Transportation Studies at UC Davis. Project partners included American Honda Motor Company, BART, Caltrans, PATH, and LLNL. INVERS and Teletrac provided advanced carsharing and vehicle tracking technologies.