Big Auto helped kill America’s best chance to curtail reckless speeding. But it’s not over yet

California Governor Gavin Newsom had a chance to make his state the national leader in preventing speeding, which contributes to roughly a third of the 42,000 annual crash deaths in the U.S. He blew it.

On Saturday, Newsom announced that he wouldn’t sign SB 961, a bill that would have required every new car sold in the Golden State to come equipped with a technology known as intelligent speed assist, which sends a visual and audio warning if the driver goes 10 mph beyond the posted speed limit. Introduced by state senator Scott Weiner, a Democrat from San Francisco, the bill had been approved by both chambers of the state legislature. Had Newsom signed it, California would have become the first state forcing automakers to adjust their vehicle designs to discourage extreme speeding. Instead, Newsom issued a veto.

Intelligent speed assist (ISA) “is a proven technology that gets people to slow down and saves lives,” Wiener texted me afterward. “This veto is deeply disappointing and a missed opportunity for California to lead on traffic safety.”

Wiener is not wrong. But given the novelty of his proposal—as well as the intensity of the opposition from automakers—it’s remarkable it came so close to being enacted. Despite Newsom’s veto, the bill has given fresh momentum to the movement to stop merely asking Americans to cease speeding recklessly, and start forcing them to.

ISA is a smarter version of the speed governor, a century-old technology that mechanically blocks a vehicle from going faster than a preset ceiling. Modern ISA technology uses GPS and cameras to identify the posted speed limit on a given roadway segment, and then activates when a driver goes more than a few miles above the legal limit. ISA comes in two versions: “Active” systems make it impossible to go faster than the top allowable speed, while “passive” ISA systems use noises, visual cues, or accelerator resistance to discourage (though not prevent) going faster. The technology can be installed either during the vehicle manufacturing process or as a retrofit afterward.

ISA has attracted growing support among policymakers and safety advocates who have noted the limitations of traditional anti-speeding tactics, which include issuing public service announcements (ineffective), expecting police to write tickets (unreliable and problematic for minorities), or installing automatic speed cameras (banned in many U.S. states).

Across the Atlantic, the European Union now requires passive ISA systems to be installed on new cars. If anything, the technology’s safety upside seems greater in the U.S., where residents are far more likely to die in a crash and many new cars can hit 130 or 140 mph, well above the highest national speed limit of 85 mph.

Last year, the National Transportation Safety Board (NTSB), which plays an advisory role in safety policymaking, called on the National Highway Traffic Safety Administration (NHTSA) to mandate ISA on all new vehicles. NHTSA hasn’t followed that recommendation, but local and state officials have been more receptive. In 2022, New York City launched a pilot program in which several dozen fleet vehicles were outfitted with ISA (with encouraging initial results), and earlier this year the District of Columbia approved a new program that will require ISA to be installed on cars owned by drivers with a history of reckless speeding.

But by far, the most audacious U.S. proposal for ISA has been Wiener’s California bill, which would have mandated the technology on any new car sold statewide (emergency response vehicles would be exempted). Because California is such a prominent market for car sales, an ISA requirement there would likely force the auto industry to install the systems across all new cars nationwide.

The California bill was scaled back as it navigated its way through the state assembly and senate. Although Wiener initially required new cars sold in 2027 to have active ISA (i.e., exceeding the maximum speed threshold would be impossible), by the time the bill arrived on Newsom’s desk it called for passive ISA (speeding drivers are warned but still able to go faster) by 2030.

Still, the fact that the bill made it through California’s legislature at all was an impressive feat. When I spoke with Wiener after he first introduced the bill in January, he said he was motivated partly by a desire to expand the Overton window for ISA, helping Americans understand that it offers a sensible way to reduce crash deaths. That goal could be accomplished even if the bill never made it out of committee (which at the time seemed possible).

Although SB 961’s original requirements were softened, automakers still lined up in opposition. They didn’t say so out loud, but their resistance may partly stem from fears that curtailing maximum car speeds would hamper their marketing of models like the Dodge Challenger, whose ads practically celebrate extreme speeding.

In public explanations of their opposition, automakers have emphasized that vehicle safety regulations should be the domain of the federal government, not states. There’s some logic to that argument: Cars are often driven across state lines, so it makes sense that one national government, rather than 50 state ones, would oversee their designs. But there is room for debate. When I spoke with Wiener in January, he told me that he believes states like California have jurisdiction to implement laws about speed-limiting technology because NHTSA, the federal regulator, has said nothing about it either way. Since there are no federal laws about ISA, Wiener claimed, states like California aren’t preempted from enacting their own.

Explaining his veto, Newsom echoed the arguments advanced by automakers, saying that California lacks the authority to require ISA regardless of its merit. But even if that were true (and it’s not clear that it is), Newsom still blew a chance to push the envelope on road safety.

Had the governor instead signed the bill and invited automakers to sue (which they almost certainly would have), media coverage of the resulting legal fights would have brought more attention to ISA’s potential to avert crashes and amplified pressure on NHTSA to finally take a stand on a safety technology that has already won support from the NTSB and European regulators. By killing the bill, Newsom prevented that process from playing out.

Nevertheless, ISA’s story is far from over. Even in defeat, SB 961 has laid the groundwork for future chapters. Thanks to the bill, more people now know about a road safety technology that is far easier to implement than fully autonomous vehicles, which automakers often tout as a breakthrough even as they dismiss ISA. At the same time, rising calls for speed-limiting technology put car companies in the awkward position of justifying their production of vehicles capable of going 50 mph faster than is permissible on any public road—something that is, at its core, indefensible. After all, if shared e-scooters are legally required to throttle their speeds on safety grounds, why not do the same with cars that are 100 times heavier?

Wiener could reintroduce SB 961 in California’s next legislative session. When I asked him if he would do that, he demurred, saying merely that “I am deeply committed to this policy.” Either way, nothing prevents reformist legislators in other states from introducing their own version of the California bill, which would force car companies to parry on multiple fronts.

Won or lost, each ISA proposal brings the technology a step closer to broad national adoption. When that day finally comes, the U.S. will take a critical step toward bringing its ongoing roadway safety crisis to a close.