WASHINGTON (AFP) - Electric carmaker Tesla announced on Sunday (Sept 11) that it was upgrading its Autopilot software to use more advanced radar technology.

In a teleconference, Tesla founder and chief executive Elon Musk said the update, which should be downloadable in two weeks for models delivered after October 2014, "very likely" would have saved the life of a Florida driver who died in May after colliding with a truck.

With the latest update, the system would have identified a "large metal object across the road", Mr Musk said.

The Florida tragedy - the first deadly crash with a driverless system - took place after Autopilot failed to detect the truck due to poor weather and low luminosity.

The radar technology - which will now be used as a primary control sensor, rather than relying on the standard camera system - easily sees through fog, dust rain or snow.

"It should work for something like a moose, because a moose is quite a big mass, but it may not work for something like a small deer," Mr Musk said.

Tesla explained that "the net effect of this, combined with the fact that radar sees through most visual obscuration, is that the car should almost always hit the brakes correctly even if a UFO were to land on the freeway in zero visibility conditions".

The company's cars, it said, will also be able to bounce the radar signal under a vehicle it is trailing and still brake, avoiding a potential pile-up should the car in front crash.

"Perfect safety is really an impossible goal," Mr Musk said in discussing the update, which was developed over the past three to four months.

"It's about improving the probability of safety. There won't ever be zero fatalities, there won't ever be zero injuries."

The Tesla chief estimated that the new system was a threefold improvement of safety, while stopping short of considering the update a recall of the old system.