App could help slash freeway deaths

Posted by Emma Woollacott

A new app to be tested in California this summer is claimed to be able to reduce freeway pile-ups by 40 percent.

While so far it's only seen action as a computer simulation, the  University of Bologna team says it's confident of good results.

"Basically, what we are doing is placing cars in peer to peer communication," says Marco Roccetti, professor of internet architecture at the university. Other than in-car Wifi, the only thing that's needed is an acceleration sensor, so that when a car is involved in a collision it can detect it and inform those behind immediately.

In a realistic scenario, with hundreds or even thousands of vehicles on an eight-lane motorway, the problem lies in making the grapevine as fast as possible and in preventing the system from being flooded, says the team.

If all cars passed on a crash message to those behind them, the maximum available bandwidth would be reached very quickly. So the system needs to be selective.

So the team's developed a technique whereby, When a car sends an accident alarm message, all those within a range of between 300 and 1000 metres receive the signal, but only one sends it on.

Rather than sending the message to the furthest car, though, it sends it to the one most likely to be able to send the signal the furthest. This might be comparatively close, with other more distant vehicles being obstructed by trucks, for example, or having less efficient transmitting equipment.

Each vehicle knows the direction and speed of all other cars around it, along with their transmitting capacity. All this information is updated every second or so.

"The technologies we are using are already mature and available," says Alessandro Amoroso, another of the project's authors. "It could be integrated directly into the car dashboard, or in the satnav. If the road tests go well, deciding whether or not to launch on the market is merely a commercial issue."