Newsweek reports on a government initiative that aims to use wireless devices in cars and traffic lights to improve safety and traffic management: Radios in cars could send messages to other cars about congestion and the radios would send alerts to sensors in traffic lights about backups and then change the timing of the lights. This article says that the department of transportation is working with automakers and wireless companies to introduce a pilot program.
It seems that Wi-Fi isn't the best solution, however. Existing cellular networks would be ideal for this type of application, which would only require the transfer of small amounts of data. But maybe using the cellular networks brings a host of cost issues along with it. But once again, building Wi-Fi networks to cover practically every roadway is a ridiculous proposition because the coverage area of one access point is just too small.