US auto regulator examining Tesla Model S cars after fatal accident

US auto safety regulators are examining some 25,000 Tesla Model S vehicles after a driver was killed in a car which had its autopilot mode operational.

The National Highway Traffic Safety Administration (NHTSA) has called for an examination of the design and performance of any driving aids in use at the time of the crash.

This is the first step the agency needs to take before it can seek an order for a recall if it believes the vehicles are unsafe.

The crash which happened on May 7 in Willlison, Florida, near Gainesville is believed to be the first US death in a vehicle engaged in a semi-autonomous driving feature.

The car is said to have collided with a tractor trailer pushing the car off the road, striking two wire fences and a power pole before coming to a rest about 100 feet away.

According to a blog post by Tesla: “Neither Autopilot nor the driver noticed the white side of the tractor trailer against a brightly lit sky, so the brake was not applied.”

Analysts say the death could hurt Tesla’s safety record and the company may opt for a voluntary recall or stop the sale of the Model S vehicles with autopilot feature.

The autopilot feature allows the car to steer within a lane as well as change lanes with the tap of a turn signal. It manages speed using active traffic-aware cruise control.

The system uses camera, radar, ultrasonic sensors and GPS.

Tesla however said customers need to acknowledge that the autopilot feature “is new technology and still in a public beta phase” and urged drivers to “maintain control and responsibility for your vehicle”.