Waymo made history on Tuesday, announcing that fully driverless cars—with no one sitting behind the wheel—were already roaming public streets near the Phoenix suburb of Chandler. It's happening way earlier than I expected it would.

Back in 2010, I made a bet with the Economist's Ryan Avent. He had an infant daughter and mused on Twitter that she might never need a driver's license since self-driving cars could be commonplace by the time she turned 16 in 2026. I was skeptical. I certainly expected self-driving cars to reach American streets eventually, but I thought it wouldn't happen until after 2026.

So we made a bet. I haven't officially lost the bet yet because the bet focuses on travel from Philadelphia to Washington, DC. But it seems pretty likely that Waymo will expand to the East Coast long before 2026, and I'll have to pay up.

My big mistake was assuming that, even if the technology became ready by the early 2020s, legal restrictions would hold up its commercial introduction. "The policy debate won't begin in earnest until prototype self-driving cars start to show safety records comparable to human-driven cars," I wrote. "And then, in the best case, there will be several years of foot-dragging by policymakers."

I was totally wrong. Instead, regulators—at the federal level and in some states, especially Arizona—have bent over backwards to accommodate self-driving car technology.

"I thought there would be a lot more pushback than we're seeing," said Caleb Watney, a policy analyst at a free-market think tank called the R Street Institute.

Ordinarily, we think of Republicans as the ones pushing for a hands-off approach to technology. And it's true that Republicans are in power both in Washington and in Phoenix. But that doesn't explain the breadth of the political consensus in favor of light regulation of self-driving cars. Auto safety regulators under Donald Trump have largely followed the path blazed by their Obama-era predecessors. Legislation to reduce regulatory barriers to self-driving cars passed the House of Representatives in a unanimous voice vote in September.

Why policymakers embraced self-driving cars

A big reason I expected self-driving vehicles to face regulatory roadblocks is that regulators normally have strong political incentives to be cautious. If you run an agency that approves a product that turns out to be dangerous, you're likely to face heaps of bad press and might lose your job. Regulators are less likely to face blame for delaying the introduction of a potentially life-saving product because the families of those whose lives could have been saved may not even know about it.

But self-driving cars are much higher-profile than a typical drug or medical device. Advocates have been effective at convincing the public and policymakers that self-driving cars have the potential to save lives.

As those advocates have pointed out endlessly in recent years, human-driven cars kill around 30,000 people per year, with 94 percent of those deaths being due to human error. It seems likely that self-driving cars could prevent most of those deaths. Which means, as Watney puts it, "every day we don't have driverless cars is another 90 to 100 people that are potentially dying."

That argument has persuaded many policymakers. The considerable lobbying muscle of Alphabet and major car companies probably helped, too. Alphabet, the parent company of both Google and Waymo, has spent $13 million on lobbying already in 2017, ranking it number seven among all groups for lobbying spending (though most of that was probably on non-car issues). Major automakers like GM, Ford, and Toyota have each spent millions on lobbying this year as well.

At the state level, competition among states has pushed things in a deregulatory direction. Uber and its trucking subsidiary Otto have clashed with state regulators in both Nevada and California. Today, the company does a lot of its testing in the Phoenix area, where Arizona law draws hardly any distinctions between conventional and self-driving cars.

Waymo believes it’s compliant with existing federal regulations

Another important factor is that auto-safety regulators have a tradition of being relatively deferential to car companies. Agencies like the Food and Drug Administration require companies to seek pre-market approval for their products. By contrast, the approach of the National Highway Traffic Safety Administration is to set out general guidelines requiring features like airbags and antilock brakes and then ask automakers to self-certify their compliance. NHTSA then relies on after-market recalls to deal with vehicles that turn out to be defective.

This approach creates a somewhat greater risk of defective products reaching the marketplace. But it also enables automakers to get potentially lifesaving innovations into the marketplace more quickly. And carmakers are large, bureaucratic organizations that have strong incentives to color inside the lines, so there's not much reason to worry about small, fly-by-night manufacturers sneaking defective products into the marketplace.

Waymo's approach to navigating federal safety standards has been to build on top of a vehicle—Chrysler's Pacifica minivan—that is already supposed to be in compliance with applicable safety standards. This is probably one reason Waymo has backed away from trying to remove the pedals and steering wheel from its vehicles. Doing that would likely require modifying federal safety standards, while Waymo believes that leaving them in place—and just not letting customers touch them—will allow the vehicles to go to market without needing to overhaul federal regulations.

Some consumer groups would like to see more disclosure

Technology companies have been "holding out for a silver bullet for the second-leading cause of accidental death in this country," says Jason Levine, the executive director of the Center for Auto Safety, a group co-founded by auto safety crusader Ralph Nader. "If all we need to do is not over-regulate it, then sure, where do I sign up. That's the atmosphere in the air."

But Levine argues that Waymo hasn't done enough to actually demonstrate to regulators and the public that its vehicles are safer than conventional human-driven vehicles.

Waymo has done significant testing of its vehicles, but it has only released fragmentary information about the results of that testing. Waymo is required to submit information about disengagements—situations in which the driver has to take over—once a year in California. But there's no parallel system in place in Arizona. So the public has no easy way to know how many miles cars have driven in the state and what kinds of problems they might have had.

"We need 'waymo' information," says Henry Jasny, a lawyer at the Advocates for Highway and Auto Safety. Last month, Waymo filed a 43-page report with federal regulators describing its safety features. Jasny wasn't impressed. "This is essentially a sales brochure," he told Ars.

Jasny argues that Waymo and other self-driving carmakers should release enough technical details to allow independent experts to check the companies' work and flag potential problems. Providing those kinds of details to regulators would also be valuable, Jasny said, because it will allow officials to be better prepared in the event of a crash or other safety problem.

"We would like to have their test data released, at least in an aggregate way, so that the public can have some idea of comparisons" between different technologies, Jasny said.