Safer at any speed

Forty years ago consumer advocate Ralph Nader launched his career with Unsafe at Any Speed, a book which harshly criticized the safety practices (or lack thereof) of Detroit's major car manufacturers. If DaimlerChrysler has anything to do with it, the sequel will be titled Safer at Any Speed. For that we will need another WiFi-related acronym: Willwarn, for Wireless Local Danger Warning. DaimlerChrysler is now conducting tests of the system, which aims to help motorists detect danger even if it is around the next bend or over the horizon. In a test at the company's European research center, five cars equipped with WLAN-based radio technology used the Car-2-X communication system to communicate details of dangerous situations--fog, black ice, obstacles such as broken-down vehicles--which were detected by their on-board sensors to following cars. The following cars were then in a position to take appropriate action such as lowering speed, changing lanes, or coming to a stop on the shoulder of the road. (Some readers may recall that DaimlerChrysler began testing similar system six years ago, in what was then called the FleetNet project, which was followed by the NOW--for Network on Wheels--program).

The system is a sort of mesh network system, with each car serving as both a receiver and a transmitter. Each car can establish an ad-hoc network with other similarly equipped cars and send a signal within a radius of about 500 meters. For vehicles outside this radio range, the cars act as relays and pass on any warnings. Another advantage of the system is that there is no need for additional sensors to detect critical situations--the information is detected by the anti-lock braking system, the electronic stability program, the steering-angle sensors, the outside thermometer and the car's navigation system.

For more on WLAN-based vehicle safety:
- see this Engineering News report