Bill to Change the Way California Sets Speed Limits Slows Down

Bikes parked in front of the California State Capitol building in Sacramento

Assemblymember Laura Friedman has been working on A.B. 2363 – a bill to fix long-standing issues with speed limits in California. In its first committee hearing this week, the bill was amended to create a task force to study the complex issue from all sides—with a tight deadline for reporting its findings.

Currently, speeds are set according to how fast people are already driving. That’s supposed to prevent speed traps, and it’s also supposed to reflect the safety of the road design. But it ignores the history of street and road design, which has focused on making it safer to drive fast—eliminating curves and trees, for example, and widening lanes. The result is that speed limits are creeping upward even though research clearly shows that higher speeds reduce safety, and the higher the speed, the less safe for all.

The first draft of Assemblymember Friedman’s bill would have made small change to the current process. That is, it would have allowed a local jurisdiction to round a speed limit down, rather than up, when performing a speed survey for the purpose of determining a speed limit. But even that was too dramatic a change for the California Highway Patrol, the Teamsters, the Auto Club, and trucking industry reps, who strongly opposed the bill. Their resistance made Assembly Transportation Committee chair Jim Frazier (D-Oakley) oppose it.

It’s not easy to pass a bill when the chair of its first committee doesn’t like it.

But Friedman persisted, meeting with a wide range of interested parties and signaling openness to discussing changes. She accepted amendments proposed by committee staff, and in the end Frazier signed on as a co-author. That move brought bipartisan support from Assemblymembers on the committee, including Republicans Catharine Baker (R-San Ramon) and Matthew Harper (R-Costa Mesa).

In the end the Assembly Transportation Committee passed it this week on a 13-1 vote, with only Devon Mathis (R-Visalia) voting against it.

It helps that bicycle and pedestrian advocates were joined by what Friedman called “an outpouring of support from local cities.” Los Angeles, Oakland, Berkeley, Watsonville, and Malibu, among others, strongly favored some version of a fix for speed limit issues. Jennifer Cohen of the city of Los Angeles Transportation Department spoke in favor of the bill at yesterday’s hearing, pointing out that LADOT had been forced to raise speed limits on “94 miles of our most dangerous streets” just so they could enforce them. The law required them to do this even though they knew that “speed is undeniably tied to the likelihood and severity of crashes,” she said.

Chair Frazier mentioned a phone call he got from L.A. Mayor Eric Garcetti, who, he said, was quite passionate about the issue.

As amended, the bill would not change anything yet. Instead, it would create a statewide Vision Zero task force to develop policies to reduce traffic fatalities. The task force would have four and a half months to report to the legislature—by May 15, 2019—giving legislators time to introduce informed bills by the 2020 session.

The task force’s report would discuss the current process for setting speed limits and how it came to be. It would also make recommendations about alternative methods for setting speed limits and gather information on existing speed-reduction policies and engineering recommendations for increasing traffic safety for all users. It would discuss differences between urban and rural areas, as well as how bicycle and pedestrian plans are affected by the speed limit rules.

The task force is not expected to start from scratch but must gather and incorporate existing studies and analyses on the subject.

While it may not be what Friedman was aiming for, the legislation is a work in progress. A task force can help inform future discussions of the issue, and even if the Governor signs the bill, there will still be work to do.

At the hearing, Friedman said she planned to keep working on the bill’s language. “I never intended this to be a standalone measure,” she said. “Enforcement, engineering, and education are also needed. The goal is to reduce collisions to zero.”

The bill now goes to the Assembly Appropriations Committee, which it must pass by May 18 before it can go to the Senate for consideration.

32 thoughts on Bill to Change the Way California Sets Speed Limits Slows Down

  1. The overriding 85th percentile rule is foolish. CVC 21400 overrides all other considerations in setting a speed limit: “the Department of Transportation or a local authority shall not reduce the speed limit any further [below the downward rounding] for any reason.” “FOR ANY REASON”. That means that, even though the California Manual on Uniform Traffic Control Devices and CVC 627 suggest things to consider such as proximate residential density, parks, pedestrians, bicycles, accident statistics, the only permissible reduction below the nearest 5 MPH increment is rounding down to the lower 5 MPH increment when rounding up would have otherwise been closer to the 85th percentile. So, if the 85th percentile is 54 MPH, CVC 21400 says that the speed limit must be rounded up to 55 MPH, and the only exception allows the speed limit to be rounded down to 50 MPH but no lower FOR ANY REASON.

    This puts the judgment entirely and exclusively in the hands of the drivers of that section of roadway. That might sound like it democratizes the process and even better by making it seem like the decision is made by a super-majority of 85%. It seems to fit into contemporary ideas of fairness and “wisdom of the crowd” and open/transparent government. So what’s the problem?

    First of all, it ignores the “vote” of all other users and nearby interested parties. The only people participating in the decision are drivers of automobiles and only while they’re driving on that section of the road during free-flowing conditions. All others are ignored.

    Second, those drivers aren’t expressing their thoughts or ideas. Their actions are being measured and being construed as a reasoned feeling of safety and comfort and are, therefore, the speed at which a reasonable person should be limited. “Feelings” of safety and comfort are simply NOT reasoned and should not be called reasonable.

    Third, it ignores all other factors that could be considered when setting a speed limit including ACTUAL reasoning.

    Speed limits on public roads are safety parameters that deserve more than “feelings” to support them. Safety parameters are an engineering challenge and SHOULD be set by qualified engineering analysis and NOT a simple statistical analysis of a single stream of data.

    The motivation behind the law requiring the 85th percentile measurement exclusivity seems to be strictly a preventative measure against larcenous speed traps. That sounds important and a prescribed simple algorithm seems like a good way to protect the driving public against the predatory authorities who take advantage of an unexpectedly low speed limit to extract fines or as a pretext for traffic stops. But instead of prohibiting the practice of creating speed traps and requiring an engineering and traffic survey that takes into account the prevailing actual speeds to support an enforceable speed limit, the law specifically forbids “any reason”.

    By using the 85th percentile rule and nothing else, the speed limit will creep upward until enough people actually feel unsafe and uncomfortable going so fast. Once there, the only option is for civil engineers to re-engineer the road to simultaneously make drivers feel unsafe at the posted speed limit while maintaining at least the same level of actual safety.

    What should happen is qualified civil engineers are called upon to analyze all the data (actual speeds, traffic volumes, accidents, citations, etc), the geometry, geography, demography, etc and then recommend speed limits.

  2. I think that raising freeway speed limits would be fine, on there roads raising speed limits would be dangerous for people outside of cars who are also using the road.

  3. No question, traffic deaths are higher with higher speed. When the question is “what causes accidents (all) ” the answer is a bit different. 30-40% of all accidents are DRIVER related. According to the NHSTA the top 6 Risky Driving Behaviors that lead to accidents are:
    1)Distracted driving; 2)Drug impaired driving; 3)Drunk driving;
    4)Drowsy driving; 5)Non-use of Seat Belts; and finally
    6)Speeding. Speeding gets the attention because it is easily measurable.

  4. California has at least a minimal control to reduce speed traps. Posted limits must not be 10 or more mph below the actual 85th percentile speeds to limit the for-profit speed traps that many cities would like to run to boost their local budgets. Every state should have such a rule.
    James C. Walker, National Motorists Association

  5. this is from a AAA report:
    Speeding affects both the probability of a crash and the severity of injuries produced by a crash. Over 100 studies, summarized in Elvik (2005) and Aarts and van Schagen (2006), document three effects of speed on crashes and injuries.

    First, the probability of a crash is approximately proportional to the square of the travel speed. Second, in a crash, injury risk is approximately proportional to the impact forces on a person, which in turn are proportional to the square of the
    impact speed.

    These two effects can be summarized in a general rule of thumb:
    When travel speed increases by 1%, the injury crash rate increases by about 2%, the serious injury crash rate increases by about 3%, and the fatal crash rate increases by about 4%.

  6. Mr. Walker’s group is pro-motorist. He stated on here about five times that “Research over the last 75+ years also shows that the vehicles at or near the actual 85th percentile speed have the lowest risks of being in a crash of any kind.” I wish he would have cited a peer review article that covered the last 75+ years instead of just using dogmatic terms like 75+ years of research. His website seems to propose that drivers are rational actors acting in everyone’s best interest. I have yet to see that hypothesis play out in Los Angeles.

    Furthermore, Los Angeles, because of the 85th percentile rule, has increased speed limits on streets that have cars whizzing past me because cars speed too fast, and these streets lack sidewalks meaning I am walking out in the street as these cars whiz past me. If Mr. Walker sees this, I’d like to see a peer review article summarizing the 85th percentile is safest for pedestrians. he argues that it is 40 mph as a best results but they just raised the speed limit to 45. So I have issues.

    The one article that suggests it is a “peer stream article” but not one single article is academic.

  7. the point is when pulling onto a roadway they should be careful, makes sure they have enough room to do so without causing an accident.
    Speed does not cause the accident, it is the driver who is pulling out, and not being careful and making sure they have enough room.
    the accident is a symptom of the problem, a driver that does not know how to judge when it is safe to pull out onto a roadway.
    “Speed” is not the issue. Driver judgement is the missing piece.

  8. Correct, as I have noted many times before. Research for over 75 years shows that posted speed limits have almost no effect on the actual travel speeds, plus or minus 0 to 3 mph. “Posted speed limits have no real effect on the actual travel speeds.” is the first axiom anyone must know to understand driver behavior.

    James C. Walker, National Motorists Association

  9. “. The key point: it is the driver who is pulling into traffic is the cause of the accident.”

    So drivers should never pull into traffic? I’m not sure what your point is?

  10. “put CLEAR warning signs before the cameras, and speeds will comply with posted limits.”

    Because speed limit signs aren’t enough for you?

  11. Hi WeaverFan420,

    If you are not already an NMA member, you should join because you “get it”. The optimum is for cities to engineer for AND post limits at the nearest 5 mph interval to the actual 85th percentile speeds on the main collectors & arterials that carry the high volumes of commuter, shopper, tourist, visitor, & commercial traffic that enhance commerce. In most urban situations, this means multi-lane main roads that operate at 40 or 45 mph AND are posted that way. This draws more traffic off the more minor streets to the main ones where efficient travel speeds are both possible AND legal – without the threat of predatory for-profit enforcement, a threat that is very real and always wrong in far too many cities.

    Then be sure pedestrian safety is enhanced with clearly signed & lighted crosswalks, proper crossing times, maybe advanced pedestrian walk signals, pedestrian demand buttons at places with low pedestrian crossings, etc.

    Cyclist safety is best achieved by separating them from the faster vehicle traffic. Bike lanes on roughly parallel more minor streets works. Many places in Europe and some in the USA use marked bike lanes on sidewalks.

    The point I was making above is just painting smaller numbers on the signs will NOT reduce travel speeds, it can increase crash risks by increasing speed variance with more passing & more conflicts, and it enables predatory for-profit speed enforcement rackets that no one should tolerate. The IIHS did a study in Boston where limits were reduced from 30 to 25 mph. The median speeds were 24.8 mph before and after, the 85th percentile speeds were 31.0 mph before and after, for an actual change in travel speeds of 0.0 mph. The only thing that changed was the percentage of drivers arbitrarily defined as “speeders” and open to predatory for-profit enforcement – a racket that no one should tolerate.

    James C. Walker, National Motorists Association

  12. Hi James,

    So I’m wondering what exactly the engineering methods would be that would make people feel less safe to travel fast. Is it installation of speed bumps, which I hate? Is it the introduction of chicanes? I’m also struggling to understand why that would be a good thing. I would think that if traffic engineering can be done to allow cars to travel faster without increasing the risk of accidents or injury to pedestrians or cyclists, that would result in greater aggregate fuel economy, reduced greenhouse gas emissions, and increased efficiency (less time on road per motorist to go from point A to point B), which would also lead to less traffic as increased efficiency would lead to fewer cars on the road. This would make me think that the goal of traffic engineering should be to increase safe traveling speeds as much as possible.


  13. In lighter traffic areas, no posted limits would work OK in most cases. In heavier traffic areas, posting the 85th percentile speed will usually lead to the best results. With 85th limits police can concentrate on the truly dangerous drivers — the drunk, the distracted, and the left-lane lollygaggers – because there will not be enough violators far enough above the safest limits for officers to be assigned to collect “road taxes” based on just speed.

    James C. Walker, National Motorists Association

  14. Hi Melanie,
    When a driver pulls in front of car going 20, 40 or 60 mph there WILL be a crash. And at 60 the crash will be worse than at 20 mph. The key point: it is the driver who is pulling into traffic is the cause of the accident.
    Someone going 60, on a road designed for a 60 or 70 mph is not inherently unsafe. 90% of the time, in an accident, the slower car is the one at fault.
    One NHTSA study found that if you are driving slower than the average speed of traffic on a roadway you are 8 times MORE likely to be involved in an accident, than if you are driving at, or above, the average speed.
    I get that it is easy to dislike someone who is driving fast. The problem is, according to multiple state and federal studies, fast does not equal un-safe.

  15. “speed is undeniably tied to the likelihood…of crashes” and “research clearly shows that higher speeds reduce safety, and the higher the speed, the less safe for all” are two thoughts that sound good but are just not true.
    Every time these kind of made up “facts” get published they keep the focus off of the real issue, and that is why so many people and groups oppose. Numerous studies have shown that speed is the 7th or 8th likely cause of an accident. Other studies show that speed is the cause of 10-12% of all accidents. Let’s focus on accident causes #1-5, or the reasons for the 88-90% of the crashes and fix those, THAT will make it safer for all.

    If the desire is to make speeds slow enough so that bikes, pedestrians & cars can all share the same lane, then you would need to have a 3 mph speed limit. Separating Bikes, Pedestrians and Autos seems like a better solution.

  16. 2) Put a speed camera every block or two, put CLEAR warning signs before the cameras, and speeds will comply with posted limits. But then the total fines collected are unlikely to pay the roughly $3,000/month/camera costs – so the cameras become a huge cost item in the budget that no city will pay.
    3) Traffic safety researchers count all crash results.
    4) This is the big truth, but cities don’t like the costs and consequences.
    5) In a few cities where there is very good transit and a high percentage of workers and visitors live mostly along the transit lines – the alternate mode travel can be a high percentage. In most cities, it cannot because of distances, housing costs, and poor transit choices.
    6) It is often the case, because most cities are starved for revenue and will take it anywhere they can get it – fairly or not. I live in a city where the highest posted limit on the many city-controlled main roads I have surveyed with Lidar is at the 36th percentile speed. Many are below the 20th percentile and one is at the 1st percentile with 99% defined as violators.

    James C. Walker, National Motorists Association

  17. Maybe I was not clear. Setting posted limits well below the actual 85th percentile speed and/or the design speed (which tend to be in a similar range) does NOT reduce the actual travel speeds enough to make any difference for safety. What it does do is enable for-profit enforcement with either officers or cameras, neither of which is ever used often enough to reduce actual travel speeds by enough to matter – because really blanket enforcement enough to reduce speeds is too expensive with no ticket profits for the budget.

    As shown in another post, engineering can change the actual travel speeds. 4) Example: If the slowest 85% of the drivers now feel safe and comfortable at speeds up to about 35 mph, then engineering changes can be made so 85% then feel safe and comfortable only at speeds up to about 25 mph.

    James C. Walker, National Motorists Association

  18. 2) because cities are unwilling to move to income-based fines and because of unwarranted political backlash on ticket cameras, not because “it costs too much.”
    3) Fewest accidents for drivers but inherently unsafe to other users, which leads to a reduction in those users from their own logical choices. That is not the same thing as an increase in physical safety.
    4) In the context above, this is true.
    5) The negative consequences of congestion are far outweighed by the increase in alternative mode use. The increase in use of the parallel streets does not often result in an increase in serious accidents as per your own reasoning, they are designed with slower speeds in mind and thus drivers move slower.
    6) This may be true but is not necessarily the case.

  19. The number of accidents is not the relative statistic – the severity is. That study is specific to non-limited-access highways which tend to be highly familiarized to drivers, and is specific to US context, which is extremely resistant to automated enforcement and to income-based traffic fines. Such a method would increase enforcement without the for-profit connotation.

    Even considering that information, you did not rebut me as the posted speed and the design speed are different.

  20. The principle is quite simple to understand. On nice days when traffic is free flowing under good conditions, authorities measure the speeds of the free flowing vehicles (not those that just entered the flow or are turning out of it – or are otherwise not proceeding at their chosen cruising speeds), and find the speed at or under which you find the slowest 85% of the vehicles. Round that number to the nearest 5 mph interval for the safest speed limit to post that tends to produce the fewest crashes. Example: If the slowest 85% of the vehicles are at or under 38 to 42 mph on a main 4 lane collector or arterial street, you post 40 mph as the limit for the best results. Research over the last 75+ years also shows that the vehicles at or near the actual 85th percentile speed have the lowest risks of being in a crash of any kind. In this example, the vehicles at or near 40 mph have lower risks of being in or causing a crash than the ones at 30 or the very few 50 mph.

    James C. Walker, National Motorists Association

  21. I have often thought that we could just eliminate speed limits on most rural Interstate highways. The police could then concentrate their efforts on the truly dangerous drivers — the drunk, the distracted, and the left-lane lollygaggers.

  22. If you read some of the traffic safety engineering research on the subject developed over the last 75+ years, you would see what is analyzed is where to put the POSTED LIMIT to achieve the fewest crashes. This is completely different than discussing the travel speeds – because they do not change by enough to matter when posted limits are raised or lowered. The best study of 100 urban and rural locations showed you could raise limits by up to 15 mph or lower them by up to 20 mph — and the maximum change to the actual 85th percentile speed was 3 mph, with the average change of 1.5 mph.

    James C. Walker, National Motorists Association

  23. “Any “study” that says higher speeds are less safe are 100% false.”


  24. I encourage you all to come listen to a discussion about how the 85% speed limits work. Thursday may 24th at LACBC headquarters 6th and Spring.

  25. Most rural Interstates should be posted at 75, 80, or 85 mph – depending on their actual 85th percentile speeds of free flowing traffic under good conditions, rounded to the nearest 5 mph interval. Texas Highway 130 is posted at 85 mph, the highest posted limit in the USA. The actual 85th percentile speed is 86 mph per data from TexDOT. It is a perfect limit and a clear example it is FALSE that “people always drive 5 or 10 over”. Correct limits are respected, artificially low ones are not.

    James C. Walker, National Motorists Association

  26. This is another bill thinly veiled to allow speed limits to be reduced and therefore more tickets to be written, and more revenue to be generated. Any “study” that says higher speeds are less safe are 100% false.

    it’s time they started focusing on the REAL problem with traffic safety — distracted driving and also certain classes of people simply being unable to drive safely (e.g. the elderly). Speed IS NOT THE PROBLEM.

  27. Facts (which the pedestrian and cyclist lobbies do not like or accept the known science)
    1) Posted limits do NOT make any significant change in the actual travel speeds.
    2) Most cities will not use enough enforcement with either officers or ticket cameras to materially change actual travel speeds because it costs too much.
    3) 85th percentile posted speed limits are almost always the safest, and they prevent predatory for-profit enforcement of speed traps that no one should tolerate.
    4) Engineering changes are the ONLY effective way to reduce the actual travel speeds by any significant amounts. Example: If the slowest 85% of the drivers now feel safe and comfortable at speeds up to about 35 mph, then engineering changes can be made so 85% then feel safe and comfortable only at speeds up to about 25 mph.
    5) The effective engineering changes may have negative consequences of congestion and diversion of traffic onto smaller roughly-parallel streets that are far less prepared for the higher volumes and speeds of the main arteries that were re-engineered.
    6) Artificially low posted limits set well below the safest 85th percentile levels are often used in for-profit enforcement rackets with most tickets going to safe drivers for the sole purpose of profits. These are larcenous rackets no one should tolerate.

    James C. Walker, National Motorists Association

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