Basic car safety systems designed to save lives in the event of an accident like seatbelts and airbags are being supplemented in modern vehicles by increasingly sophisticated preventative technologies such as ABS and lane departure warning systems. The next step in the evolution of collision prevention technology is vehicle-to-vehicle and vehicle-to-infrastructure communications systems like that found on the LTE Connected Car and BMW's Vision ConnectedDrive concepts that would allow vehicles to share information on their relative location and road conditions. GM has recently announced it is testing small, portable devices that create a "wireless safety net" to gather information from other vehicles and infrastructure to warn drivers of potential hazards.

The effectiveness of vehicle-to-vehicle and vehicle-to-infrastructure communications systems improves as more and more people use it. According to GM the average age of U.S. vehicles is 10.2 years, so the company is striving to develop systems that are affordable and could be easily fitted to existing vehicles. To this end it has been testing the technology in two mobile platforms - one is a transponder about the size of a GPS unit, while the other is a smartphone application. While the portable transponder has its own display screen, a smartphone can be connected to the vehicle's audio and video display for use with the smartphone application.

As well as using basic location data, the portable devices can also be connected to the vehicle's computer system to relay information being collected by sensors throughout the vehicle. Sensors that activate electronic stability control could be used to warn other drivers of hazardous road conditions, or a string of drivers can be warned when the head vehicle applies the brakes, for example.

The system relies on Dedicated Short-Range Communications (DSRC) that, with a range of about one-quarter mile (400 m) in all directions, can send and receive messages with other vehicles in the area and with radios connected to traffic lights or construction zones.

"The technology we're testing right now is a viable solution for providing crucial safety information to drivers," said Don Grimm, senior researcher for GM's Perception and Vehicle Control Systems group. "Instead of just seeing what's right in front of them, drivers will be able to know about the truck a quarter-mile ahead that's stalled in their lane. Later this decade, smartphones, transponders and embedded systems could be working together to make our roadways safer."

GM says an added benefit of using smartphones for such a system is that it could potentially be used by pedestrians and cyclists who could download a special app that would let drivers know their location.

Quoting a study by the National Highway Traffic Safety Administration, GM says vehicle-to-vehicle and vehicle-to-infrastructure communication systems could help avert nearly 81 percent of all U.S. vehicle crashes. But the key to realizing the potential of this technology is ensuring systems embedded in different makes of vehicles are compatible with each other. Time will tell whether the various automakers can get together and work towards a universal standard to ensure such systems live up to their life-saving potential.

GM is showcasing its portable transponder and smartphone application at the Intelligent Transport Systems World Congress running in Orlando this week.