Will Tesla's Autopilot accident put the brakes on autonomous car development?

As US investigators begin examining the first recorded incident of a motorist being killed in an accident while driving a car with its autonomous driving features engaged, questions are being raised about the rate at which we're moving to a self-driving future.

The car in question was a Tesla Model S with the Autopilot system engaged. According to initial findings, its sensors failed to detect a tractor trailer pulling across the road ahead and collided with it, killing driver Joshua D. Brown in the process.

In a statement, Tesla said: "Neither Autopilot nor the driver noticed the white side of the tractor-trailer against a brightly lit sky, so the brake was not applied. The high ride height of the trailer combined with its positioning across the road and the extremely rare circumstances of the impact caused the Model S to pass under the trailer."

Tesla also highlighted that that iAutopilot's launch owners have driven over 130 million accident-free miles. "Among all vehicles in the US, there is a fatality every 94 million miles. Worldwide, there is a fatality approximately every 60 million miles," it said.

However, the US Consumer Watchdog is now calling on the National Highway Traffic Safety Administration (NHTSA) to tighten legislation regarding how such cars are allowed on to the roads and to fully examine this particular accident and use its findings to steer future laws.

"We hope this is a wake-up call to federal regulators that we still don't know enough about the safety of self-driving cars to be rushing them to the road," said Carmen Balber, Executive Director with Consumer Watchdog. "If a car can't tell the difference between a truck and the sky, the technology is in doubt."

Making certain that different types of sensor perform in exactly the same fashion regardless of whether it is day or night, if the sun is shining brightly or if the rain is pouring is why firms such as Volvo, BMW, and Nissan are completing mile after mile of real-world testing with bigger and bigger fleets.

The Consumer Watchdog's concerns are valid, even if there is only one car on sale in the US that comes with a highway autopilot system as standard -- the Volvo S90 sedan. However, what is also clear is that semi-autonomous systems such as low-and-high-speed Autonomous Emergency Braking (AEB) are already proving themselves invaluable at reducing accidents. "Data shows that higher speed AEB systems have the potential to reduce injury crashes by up to 45 percent," said Matthew Avery, Director of Research at Thatcham Research, the independent British body set up to assess vehicle crashes and new-car safety.