The debate over the safety of self driving cars has been brought sharply into focus following the death of two Tesla vehicle occupants in a single vehicle accident in Texas.

Eye witnesses at the scene say that no one was in the driver seat of the Model S when it crashed into a tree. However, Tesla CEO, Elon Musk, said checks by Tesla technicians indicated that the car’s Autopilot driver assistance system was not engaged at the time of the fatal crash. Texas police have now served warrants on Tesla to secure data from the vehicle.

This is the 28th accident involving Tesla cars that has been investigated by the National Highway Traffic Safety Administration in the USA.

It is believed the 2019 Tesla Model S was travelling at high-speed on a road near Houston and failed to negotiate a corner before hitting the tree and bursting into flames. Police later located two bodies in the vehicle, one in the front passenger seat and the other, who was the owner of the car, in a rear seat. The police say they also have witness statements saying that the two men went to test drive the Autopilot system on the car with neither in the driving seat.

The Auto pilot system is a driver assistance system which does allow the vehicle driver to let the system handle some driving tasks and on limited occasions take their hands off the wheel. However, Tesla state that it requires active driver supervision and does not make the vehicle fully autonomous.

Commenting on the incident UK insurance accident research organisation, Thatcham Research, called it “An incredibly sobering illustration as to why education and correct naming are so important to the safe use of driver assistance systems. A lack of understanding of system capability is causing confusion around driver responsibility, and accidents like this sadly back that up.”

Thatcham reiterated its calls for governments, carmakers and insurers to collaborate to develop effective safety assurance and consumer education schemes ahead of the introduction of Automated Lane Keeping systems. It also said that car makers should not use system names that may mislead drivers as to their true intentions and capabilities.