Any future regulation will be hammered out between diametrically opposed camps. On one side are safety advocates, who say autonomous driving features, like those that control speed, steering and braking, should be proved safer than drivers before they are allowed on public roads. On the other side are car and tech industry backers, who say those features cannot become safer than humans without unfettered testing in the real world.

The question facing regulators, carmakers and the public is: Does regulation makes us safer, or will it slow the adoption of technology that makes us safer?

Safety proponents may disagree over what testing should be required, but they agree there should be some standard. “You can’t anticipate everything,” said Phil Koopman, an expert on safety standards for autonomous cars. “But the car industry uses that as an excuse for doing nothing.”