The first step is to allow vehicles to communicate with each other. I'm the operations lead for the Connected Vehicle Test Bed located in Novi, MI. We have 50 plus road side units that communicate with devices on the vehicles. There is a safety pilot test being run in Ann Arbor involving over 2800 vehicles. The data will allow NHTSA to determine if they need to mandate the inclusion of DSRC related devices in vehicles for safety. 802.11p is the wireless standard being used, and the vehicle specific messages are defined in J2735.
Its not far off!
http://www.its.dot.gov/safety_pilot/index.htm
http://www.its.dot.gov/connected_veh...y_testbed2.htm