General Motors Chairman and CEO Mary Barra updates the media on the company's autonomous vehicle development program, Tuesday, June 13, 2017, at GM's Orion Assembly in Lake Orion, Mich. Barra stands next to a self-driving Chevrolet Bolt EV, one of 130 the company has built at a factory in suburban Detroit, making it among the first automakers to mass produce self-driving vehicles. (Jose Juarez/Detroit News via AP)

INTERNATIONAL - General Motors’ self-driving unit, Cruise Automation, told California regulators that its vehicles were involved in 6 crashes in the state in September, but said none of automated vehicles were responsible.

The accidents did not result in any injuries or serious damage, according to the GM reports, but did demonstrate the challenges for developers of self-driving cars confronted by crowded urban streets.

A US Senate panel on Wednesday approved legislation that would allow carmakers to greatly expand testing of self-driving cars. Some safety groups have objected to the proposal, saying it gives too much latitude to carmakers.

The incidents also demonstrate the difficulties of self-driving cars that obey all traffic laws coexisting with less careful human drivers. In total, GM Cruise vehicles have been involved in 13 crashes reported to California regulators in 2017, while Alphabet’s Waymo vehicles have been involved in three crashes.

California state law requires that all crashes involving self-driving vehicles be reported, regardless of severity.

Most of the crashes involved drivers of other vehicles striking the GM cars that were slowing for stop signs, pedestrian or other issues. In one crash, a driver of a Ford Ranger was on his cell phone when he rear-ended a Chevrolet Bolt that was stopped at a red light.

In another instance, the driver of a Chevrolet Bolt noticed an intoxicated cyclist in San Francisco going the wrong direction toward the Bolt.

The human driver stopped the Bolt and the cyclist hit the bumper and fell over. The bicyclist pulled on a sensor attached to the vehicle causing minor damage.