If confirmed, it would be the third time a Tesla in autopilot has crashed into a stationary emergency vehicle this year

A Tesla car operating in “autopilot” mode crashed into a stationary police car in Laguna Beach, California, leaving the driver injured and the patrol vehicle “totalled”, according to an official.

Sgt Jim Cota, the public information officer for the Laguna Beach police department, tweeted photos of the accident, which was reported at 11.07am on Tuesday. The driver of the Tesla, who suffered minor lacerations to the face from his glasses, told police officers the Tesla was in the semi-autonomous mode, although further investigation is needed to confirm this.

Laguna Beach PD PIO (@LBPD_PIO_45) This morning a Tesla sedan driving outbound Laguna Canyon Road in “autopilot” collides with a parked @LagunaBeachPD unit. Officer was not in the unit at the time of the crash and minor injuries were sustained to the Tesla driver. #lagunabeach #police #tesla pic.twitter.com/7sAs8VgVQ3

Cota told the Guardian that the Tesla sedan’s front end was “pretty beat up” and that the police SUV was a “complete total loss”.

He said: “It was mangled up pretty good. It took out the whole back end and halfway through the centre part of the vehicle. There’s axle damage. It wouldn’t be worth repairing.”

If confirmed, the incident will mark at least the third time a Tesla in autopilot has crashed into a stationary emergency vehicle since January. This month, a Tesla Model S crashed into a stopped firetruck in Utah, echoing a similar incident in January, when the same model collided with a stopped firetruck on the 405 freeway in Los Angeles county.

Culver City Firefighters (@CC_Firefighters) While working a freeway accident this morning, Engine 42 was struck by a #Tesla traveling at 65 mph. The driver reports the vehicle was on autopilot. Amazingly there were no injuries! Please stay alert while driving! #abc7eyewitness #ktla #CulverCity #distracteddriving pic.twitter.com/RgEmd43tNe

Cota noted that another Tesla had collided into a stationary semitruck in the same area in April 2017.

A Tesla spokeperson said: “When using autopilot, drivers are continuously reminded of their responsibility to keep their hands on the wheel and maintain control of the vehicle at all times.

“Tesla has always been clear that autopilot doesn’t make the car impervious to all accidents, and before a driver can use autopilot, they must accept a dialogue box which states that ‘autopilot is designed for use on highways that have a center divider and clear lane markings’.”

Failing to detect stopped vehicles is a known problem for makers of cars with autonomous features. Tesla’s manual warns: “Traffic-Aware Cruise Control cannot detect all objects and may not brake/decelerate for stationary vehicles or objects, especially in situations when you are driving over 50mph (80kmh) and in situations where a vehicle you are following moves out of your driving path and a stationary vehicle or object is in front of you.”

Tesla that crashed in Autopilot mode sped up before hitting truck – police Read more

As highlighted by Wired following the January collision with a fire truck, Volvo’s semi-autonomous system is similarly ill-equipped to deal with such a scenario. If a car in front of a Volvo using “pilot assist” changes lanes, revealing a stopped car in front, “pilot assist will ignore the stationary vehicle and instead accelerate to the stored [cruise control] speed”.

This quirk is generated by the systems’ efforts to avoid false positives and slamming on the brakes unnecessarily, which could also be dangerous. The radar sensors used on the cars detect other vehicles on the road, but also stationary objects such as overhead road signs. Engineers have to program the system to focus on moving objects to ensure the car doesn’t brake every time it “sees” a road sign.

Auto makers can improve the accuracy of their autonomous systems by using multiple sensor types, including lidar, which projects lasers that bounce off objects to create a high-resolution map of the environment. It is expensive but provides visibility where other sensors, such as radar and cameras, fail. Many experts believe lidar will be critical for building successful fully autonomous vehicles.

Tesla’s CEO, Elon Musk, is not one of them. During a February earnings call, he referred to lidar as “expensive, ugly and unnecessary”.