If Drivers Won’t Slow Down, Proposed New Law Requires Cars Do It for Them

Speed kills. On the roadways, that is. In 2021, almost one of every three deaths in United States traffic was caused by a speeding-related crash, according to a study by the National Highway Traffic Safety Administration. That was 12,330 deaths nationwide, due at least in part to drivers going too fast.

Excessive speed was deadlier in California than in the rest of the U.S. In 2021, according to figures from the UC Berkeley Safe Transportation Research and Education Center, 1,509 people were killed by speeders.

A new law introduced in the California Senate last week would, if passed, use “intelligent” technology to make it physically impossible to speed—or at least not at rates more than 10 miles per hour above the speed limit. 

Excessive speed was even deadlier in California than in the rest of the U.S. In 2021, according to figures from the UC Berkeley Safe Transportation Research and Education Center, 1,509 people were killed by speeders. That’s 35 percent of all traffic fatalities in the state. 

California has been trying to take at least some steps to rein in the traffic bloodbath. In 2021, Gov. Gavin Newsom signed AB43, a new law that allows local governments to lower speed limits on streets and roads, including state highways, that have been designated as “safety corridors.” But can’t local governments just set their own speed limits anyway? Until AB43, the answer was no.

‘85th Percentile Rule’ Lets Cars Go Faster

Governments were required to follow the “85th percentile rule,” which meant that speed limits must reflect the actual speeds at which 85 percent of drivers travel on a given stretch of road. The rule is based on the assumption—one proved faulty by research by the University of California Institute of Transportation Studies—that drivers themselves can determine the safest possible speeds.

A proposed new California law would take the job of setting their own speeds out of the driver's hands entirely. SB 961 would require that new cars and trucks sold  in California come equipped with an “intelligent speed limiter system.”

By following that rule speed limits went up more than they went down. Not a very surprising result considering that, according to a 2019 survey  by the AAA Foundation for Traffic Safety, 40 percent of drivers admit to regularly driving at least 10 miles per hour over the speed limit in residential areas. The UC Institute research also showed drivers do a poor job of regulating their own speeds. In the study, drivers consistently underestimated their own speeds by up to 30 percent when driving on roads with a speed limit up to 35 mph. 

Proposed Law: Speed-Limiting Technology Required by 2027

Now, a proposed new California law would take the job of setting their own speeds out of the driver's hands entirely. SB 961, introduced on Jan. 23 by San Francisco Democrat Scott Wiener, would require that new cars and trucks sold or built in California come equipped with an “intelligent speed limiter system.”

Under the law this technology, also called a “speed governor,” would prevent any vehicle in which it is installed from moving at more than 10 mph above a posted speed limit.

Under the law this technology, also called a “speed governor,” would prevent any vehicle in which it is installed from moving at more than 10 mph above a posted speed limit. Emergency vehicles would still be allowed to go without the speed governor, and the new technology requirement would not kick in until 2027. In certain instances, drivers would be able to shut off the speed limiting technology.

California would be the first state to require that cars come equipped with speed limiting tech, if the bill were to pass. But the state is not alone in considering the move. In 2023, the National Transportation Safety Board called for all new cars to include speed limiting technology.  

NTSB Also Calls for Speed-Limiting Tech in New Cars

The NTSB recommendation was a response to a gruesome traffic accident in North Las Vegas, Nevada, on Jan. 29, 2022. In that horrific incident, the driver of a 2018 Dodge Challenger—under the influence of cocaine and PCP (aka “angel dust”)  blew through a red light at 103 miles per hour, slamming into a Toyota minivan in the intersection, killing all seven people in that vehicle. The driver and another person in his passenger’s seat also died.

Wiener’s SB 961 bill also requires large trucks sold in California to come with side guards that prevent bicycles and even other cars from being pulled under the truck in the event of a crash.

In its investigation, the NTSB “found that an intelligent speed assistance (ISA) system that electronically limits the speed of the vehicle may have mitigated the severity of the North Las Vegas crash.” In other words, speed-limiting tech could have saved the lines of at least some of the nine people who lost their lives that day.

A similar incident occurred in Los Angeles on Aug. 4, 2022 when a 37-year-old nurse ran her Mercedes-Benz through an intersection at 130 miles per hour, according to court records cited by the Los Angeles Times, killing six people including a one-year-old child. The nurse, Nicole Linton, survived the crash with only minor injuries but according to later reports had a history of psychotic episodes possibly caused  by frontal lobe seizures.

If indeed she was experiencing one such episode at the time of the crash, which has not been determined, speed-limiting technology could have prevented her from hitting such extreme speeds, potentially reducing loss of life in the crash.

Wiener’s SB 961 bill also requires large trucks sold in California to come with side guards that prevent bicycles and even other cars from being pulled under the truck in the event of a crash. The European Union already mandates side guards for some trucks.