Gov. Greg Abbott signed a bill Thursday that signals to Google, Uber and carmakers that they are welcome to test self-driving cars on the state's roads and highways without a driver behind the wheel.

There was nothing in existing law that banned autonomous vehicles from Texas roads. After all, Google has been testing them since 2015 in Austin, and Arlington is rolling them out. And several Texas sites were chosen by the U.S. Department of Transportation to test the technology in closed-course settings. Yet because state statutes didn’t address the emerging technology at all, some manufacturers have told state officials they were wary about testing vehicles alongside street and highway traffic in Texas.

“The lack of laws credited a need for clarity,” state Sen. Kelly Hancock, R-North Richland Hills, said at an April hearing on his bill.

Senate Bill 2205 requires driverless vehicles used on highways be capable of complying with all traffic laws, be equipped with video recording devices and be insured just like other cars. It also makes the manufacturer responsible for any broken traffic laws or car wrecks, as long as the automated driving system hasn’t been modified by anyone else.

It’s unclear if the new law will lead to Texans regularly commuting next to cars that don’t have an operator — or anyone — inside.

Texas is now among 18 states that have passed bills related to autonomous vehicles. It's among three states that have done so in recent months. Many manufacturers, including General Motors and Toyota, backed the bill.

“It sends all the right signals to GM or anybody else that’s embracing the technology,” said Harry Lightsey, GM’s executive director of emerging technologies policy.

Does that mean the auto manufacturer will soon be operating empty vehicles on Texas highways?

“We have not publicly said what our plans may or not be for the future,” Lightsey said.

The company is testing autonomous cars in three other states. But there’s always an operator in their vehicles in case a human needs to take over driving. Lightsey said it could be a while before the company feels comfortable operating a vehicle in traffic without anyone inside.

“We’re not going to do it until we have the data that fully convinces us we can do that safely,” he said.

AAA Texas would have preferred that the new state law required a human operator be in the vehicle. The group also wanted minimum insurance coverage to be $1 million, instead of the lower coverage levels all other cars on Texas roads are required to maintain. But the bill made it through both chambers without the organized opposition a similar attempt faced two years ago.

Lawmakers and experts said the technology has the potential to dramatically reduce road fatalities and provide a new transportation option to disabled Texans.

“The technology has tremendous potential to make everybody safer on the road,” Lightsey said. “It also has tremendous potential to enhance quality of life for a lot of people.”

Disclosure: Google, Uber, General Motors, Toyota and AAA Texas have been financial supporters of The Texas Tribune. A complete list of Tribune donors and sponsors is available here.