Japanese researchers will test a new collision avoidance system on the country's roads in April.

The new technology relies on radio communications between specially adapted vehicles.

Developer Denso Corp, which does not make cars, declined to say whether it is working with any particular manufacturer on the new safety system. The company has been closely affiliated with Toyota in the past.

"Denso will conduct vehicle-to-vehicle communication using its devices at between 669MHz and 679MHz, and 5811.5MHz and 5828.5MHz, to measure noise and other conditions while vehicles are travelling," the company announced.

The tests will be restricted to roads on the northern island of Hokkaido, and are expected to last until March 2011.

"Through these tests, we expect to improve the performance and reliability of our in-vehicle devices to provide stable communications," said Oyuki Ogawa of Denso's engineering research and development centre in Hokkaido.

Denso is also working with other companies elsewhere in Japan on navigation and safety systems that rely on vehicle-to-vehicle and vehicle-to-road communications.
Toyota recently announced a prototype in-car camera and image analysis system that detects when a driver falls asleep at the wheel and automatically applies the brakes.

In 2006, rival Japanese car maker Nissan began large scale public road tests of a system that warned drivers of impending collisions with other vehicles and alerted them if they approached red lights or road hazards too rapidly.