A new safety feature being developed by Nissan Motor Co. causes a car’s gas pedal to lift by itself to alert the driver of a possible collision.

That new technology combines radar sensors and a computer system to judge a car’s speed and the distance to the vehicle in front.

When the car senses a possible head-on crash, the gas pedal automatically rises against the driver’s foot as a signal to step on the brake.

If sensors detect a possible collision ahead, the brake automatically kicks in when the driver lifts his or her foot off the gas.

A buzz also goes off in what Nissan engineers tentatively dubbed the “magic bumper.”

Skeptics may see the technology as obtrusive, perhaps even risky, given that some drivers may prefer to rely on their own reflexes.

But Nissan says the magic bumper is helpful because research has shown that more than half of traffic accidents are caused by inattention, drowsiness and carelessness.

Senior manager Yousuke Akatsu said Nissan hoped to offer the safety feature in about two or three years in Japan and also aimed to offer it in the United States and Europe, although no plans have been set.