If you live a block off Venice, Olympic or La Cienega, you have probably already had the conversation. The cameras go up on the boulevard, drivers who hate them start cutting through the residential street behind it, and suddenly your quiet block is somebody's bypass. It is the most reasonable worry anyone has raised about LA's program, so here is what the evidence says.
What the research found
First, diversion has been studied less than you would expect. A national traffic safety review from NHTSA notes "very limited examination of spillover effects, including the possibility of traffic or crash diversion" in at least one major camera study. So nobody should tell you the question is settled.
What has been studied mostly points the same way. Research on 62 British camera sites with 30 mph limits, summarized in a 2010 RAC Foundation review, estimated that about 5% of traffic had been diverted for no other apparent reason. A larger study of 771 camera sites in England found "no evidence of accident migration," meaning crashes did not simply move to nearby roads. A 2021 study of Dayton, Ohio concluded, "If spillovers do exist, I find little of them here."
The most interesting result comes from Montgomery County, Maryland. Researchers with the Insurance Institute for Highway Safety found that the share of drivers going more than 10 mph over the limit fell about 70% at locations with cameras and warning signs, 39% at locations with signs but no cameras, and 16% on residential streets that had neither. Speeding near the cameras went down, not up. Drivers seemed to slow down across the area, not just in front of the lens.
San Francisco's results hint at something similar. A preliminary UC Berkeley SafeTREC analysis found speeding declined at comparison sites as well as camera sites, though the camera locations improved faster and further. The full picture is in my breakdown of other cities' results.
Why LA could be different
Our grid gives drivers options. Olympic has Pico. Venice has Washington. A side street that parallels a camera segment for a mile is exactly where a determined driver could try to make up time. And cameras sit on segments, not whole corridors, so a driver who slows down for one stretch can speed up again a few blocks later. Those are real differences from a suburban county, and LA will have to measure its own.
The good news is that the law requires LADOT to report speed and collision data before and after installation, and the city has every reason to watch the parallel streets too. Residents who notice a change should say so early, in writing.
What to do if your block changes
Write down what normal looks like now, before the fines start in late December. A few timed counts from your front window, the hours when it is worst, a photo or two. Anecdotes lose arguments. Notes from October win them.
Then take it to your council office and your neighborhood council. Do not count on the speed hump program: LADOT stopped taking new requests in 2025, its funding was cut to $715,000 a year, and its own estimate to finish the corridors already identified is close to 40 years. The better lever is the camera money. State law requires surplus fine revenue to be spent on traffic calming within three years, and that money is not limited to the camera streets themselves. I laid out how that money flows in a separate post.
When you write in, ask a specific question: are the residential streets parallel to the camera segment being counted too? A precise request gets a precise answer. A general complaint gets a form letter.
For owners and agents on parallel streets
If you are selling a block off a camera corridor, do not promise buyers anything in either direction. Nobody knows yet. If cut-through traffic does pick up, it becomes the same neighborhood traffic question your disclosure forms already ask about, and it deserves the same honesty.
The likeliest outcome, if LA looks like Maryland, is a little calmer everywhere and a lot calmer at the camera. The worst outcome is one where nobody wrote anything down. Start the notes.
This summarizes published research and AB 645's requirements in plain English. It is not legal advice, and outcomes in Los Angeles may differ from the studies cited.
