General Motors delayed the introduction of its Tesla-like Super Cruise system because of safety concerns.

“They don’t deploy it because they know that things can fail,” said Raj Rajkumar, a computer engineering professor at Carnegie Mellon University who leads its autonomous vehicle research.

Automakers have been slowly adding driver-assist features to their vehicles for years in an effort to make occupants safer and meet U.S. and European government mandates. Mercedes introduced adaptive cruise control, which automatically maintains a distance from cars in front, in 1999, four years before Tesla was founded. Ford introduced automatic parallel parking in 2009, six years before Tesla did.