Tesla CEO Elon Musk says the electric car company is making major improvements to the Autopilot system used by its vehicles, which will reduce the number of crashes in which they are involved. The news comes in the wake of a May crash involving a Tesla Model S that was using the semi-autonomous mode at the time. The driver died after crashing into a tractor-trailer.

On a conference call with reporters, Musk said he thinks that the improvements, which will roll out globally in the next week or two in the form of a software update, probably would have prevented that crash.

Musk called the upgrades a "massive enhancement," but he said that Tesla cars are already the safest on the road.

While he acknowledged that there's no such thing as perfect security, he predicted that the improvements will cut the accident rate for Tesla vehicles by more than half.

Tesla's Autopilot system can maintain a set speed, keep the car within its lane and brake automatically. Radar, currently helps the car see things that may be blocked to cameras in bright sunlight or bad weather.

According to Tesla, one of the biggest challenges was the need to eliminate false positives. While slamming on the brakes is crucial if a driver is about to hit another vehicle, it isn't if they're about to hit something smaller, like garbage in the road. And these kinds of stops always have the potential to cause injury, making a false positive potentially dangerous.

But Musk said the company was eventually able to solve that problem through software improvements.