Uber has resumed testing of robot cars in San Francisco, two years after one caused a fatal accident in Arizona.

As the race to create robot cars intensifies, a secondary race is underway: a high-stakes competition to develop the sensors that serve as the cars’ “eyes.” Lidar, a light-sensing form of radar, provides vision for the vast majority of autonomous vehicles being developed, but now there are dozens of companies with different twists on it.

U.S. lawmakers have applied a light touch in regulating robot cars. At the national level, the Trump administration has proclaimed that driverless-car guidelines should be “entirely voluntary” for automakers, and bills pending in Congress would clear the way to putting tens of thousands of autonomous cars on the road — orders of magnitude more than the few hundred in the country today — before federal safety regulations are set.

Days after a fatal self-driving-car collision in Arizona, six makers of driverless vehicles came to San Francisco on March 22 to demonstrate their technology — and emphasize its safety features — to city leaders and public-safety officers.

Police in Tempe, Ariz., on March 21 released dashcam videos of the fatal accident March 18 in which an Uber car operating in autonomous mode struck and killed a pedestrian, showing the car did not slow down or alter its course to avoid her.

It’s a paradox: How can paying a quarter of a billion dollars to a rival and issuing an apology be considered a win?

Travis Kalanick got some vindication in court on Feb. 7. Under friendly cross-examination by a lawyer for Uber — the ride-hailing company he co-founded and led until it ousted him last June — Kalanick got a chance to present himself as an earnest guy who loved his work, cared about the future and didn’t take illicit shortcuts as he competed aggressively in the race for self-driving cars.

Subdued. Calm. Compliant. Agreeable. Those adjectives aren’t typically associated with Travis Kalanick, Uber’s combative co-founder. But during 50 minutes on the witness stand in the Waymo vs. Uber trial on Feb. 6, a suit-and-tie-clad Kalanick kept his cool, meekly agreeing with most questions posed to him by Charles Verhoeven, Waymo’s lead attorney.

Waymo and Uber lawyers squared off in a federal court on Feb. 5 on the first day of a bombshell trade-secret theft case.

U.S. drivers are still cautious — but they’re getting used to the idea of self-driving cars.