125,000 Speeding Deaths Later, the Safety Establishment Admits Enforcement Isn't Working. Its Fix Is a PDF.

In May, the Governors Highway Safety Association published a manual teaching states how to put speed-limiting computers in cars.^[1] Tucked inside the announcement was a sentence worth reading twice. “Speeding-related deaths remain a vexing problem and traditional approaches have only been modestly successful,” said GHSA CEO Jonathan Adkins.^[3] I ran the numbers on “modestly successful.” Then I ran them again. They didn’t get better.

Here is the full ledger: speeding killed 11,288 Americans in 2024, which was 29 percent of all traffic fatalities.^[4] NHTSA’s early estimate for 2025 puts the number at 10,035, an 11 percent decline.^[4] That decline, still five figures a year, is the “modest success” being described.

So what does the guidebook actually prescribe for states willing to listen? Active Intelligent Speed Assistance: GPS and sign-recognition tech that physically prevents the car from exceeding the posted limit. GHSA wants it in state highway safety plans, in government and contractor fleets, in the cars of teen drivers learning the ropes, and on the radar of the judges who sentence the worst offenders.^[1] It is a voluntary-adoption playbook, state by state, fleet by fleet. Two years ago, the European Union simply mandated ISA in every new car.^[9] America got a PDF.

Now for the part that should annoy you. The technology works, and we have the receipts. New York City’s fleet pilot cut speeding 64 percent versus control vehicles, with 99 percent of miles at or below the set threshold.^[5] A Washington, D.C. pilot across 80 fleet vehicles recorded a 91 percent reduction in speeding occurrences.^[1] An IIHS study prepared with the Volpe Center found one carrier cut preventable collisions 30 percent after installing active ISA, and another watched its safety score fall from 65 to 20.^[6] Even advisory ISA, the kind that only nags, was modeled to cut road deaths 8.4 percent fleet-wide in New South Wales.^[7]

Take the most conservative number in that pile and do the math. 8.4 percent of 2024’s 11,288 speeding deaths is roughly 950 lives a year, from the weakest version of the technology, deployed everywhere. Active systems on fleets, teens, and court-ordered persistent speeders plausibly reach two to three times that. At guidebook pace, a few state laws a year and a few dozen fleet pilots, reaching even the easy slice takes a decade. That is another 100,000-plus speeding deaths in the interim, while the manual circulates.

And here is the contradiction nobody at the federal level wants to discuss. In January, NHTSA and FMCSA withdrew the heavy-truck speed limiter mandate, arguing the benefits were too uncertain to quantify. Six months later, GHSA published a deployment manual for the same class of technology, citing pilot data showing 64 to 91 percent speeding reductions: same evidence base, opposite conclusions. The feds won’t mandate what the states are now begging each other to adopt voluntarily.

To be fair to the PDF, there is a serious argument that a mandate would fail where the guidebook might succeed. Europe’s ISA mandate is routinely overridden; drivers defeat it with a kickdown or a settings toggle, and compliance studies show large fractions simply switch it off. A resented universal rule may save fewer lives than a targeted one that sticks. The guidebook aims at the populations where acceptance is highest and override is hardest: fleets whose drivers can’t toggle anything, teens whose parents hold the keys, and the worst repeat offenders a judge can order into the program. New York City’s own pilot needed a grace threshold, only engaging past 11 mph over the limit, to be tolerable.^[5] The honest version of the strategy is not “govern every car.” It is “govern the cars most likely to kill someone.”

What this misses, and the guidebook’s funders explain why: the manual was underwritten in part by the SteerSafe Partnership, a coalition of companies that sell active ISA systems.^[1] That does not invalidate the DOT-evaluated pilot data. It does mean the document recommending ISA adoption was paid for by ISA vendors, and its “up to 22,000 fatal crashes prevented per year” headline is an advocacy ceiling, not a finding.^[2] Treat it as marketing with footnotes.

Here is what you can actually do with this. If you run a fleet, the pilots say ISA pays for itself in fewer crashes, fewer tickets, and lower maintenance, and the IIHS/Volpe study is a free implementation manual.^[6] If you are a parent, ask your state’s highway safety office whether teen ISA programs exist; four jurisdictions (D.C., Virginia, Washington, Maryland) already require ISA for high-risk drivers, and five more states have bills in play this year.^[2] And if you are a lawmaker: the EU did this in one regulatory act. Every year of guidebook-paced voluntarism costs roughly eleven thousand lives. The manual is good; a mandate would be faster.