Explanation of Rising Speed Limits: “The Public Votes with the Gas Pedal”


In recent weeks, CityWatch has done a fantastic job explaining why speed limits are rising throughout the city and why those limits are determined by speeding drivers and not the communities that have to deal with the speeding traffic.

State law requires that speed limits are periodically reviewed for traffic laws to be enforced with radar guns, but the method to determine the appropriate speed is designed to protect speeding traffic not the communities they pass through.  First, a speed study is done during non-peak hours to determine how fast people are currently driving on the road.  Then, the proposed new speed limit is set at the highest 85th percentile.  In short, if 100 people drive down a road with a thirty five mile per hour limit, and 85 of them drive down it at 45 miles per hour; the speed limit will rise by ten miles per hour.

When the practice of raising speed limits was questioned at a recent City Council transportation committee hearing, an LADOT representative explained that raising speed limits to cater to fast moving cars is a sign of a healthy democracy.  "The public votes with the gas pedal," he explained.

Perhaps it’s time for some voter suppression.

If people are routinely speeding on local streets, why isn’t the answer to more consistently enforce the  speed limit?  If drivers know there are enforced speed limits around certain areas, they slow down.  If so many cars are going 5 to 10 miles over the speed limit that a traffic survey discovers that one in five drivers are confident to speed around local streets that is more a reflection on a city that sees fast moving cars as the goal of its transportation planning then anything else.

Let’s be clear.  Study after study find that fast moving vehicles on local roads kill pedestrians at a rate that dwarfs the amount of American soldiers killed overseas every year; yet enforcement of laws to slow down traffic and save pedestrian lives is so lax in Los Angeles that state law is actually forcing speed limits to rise on our streets and roads.

Perhaps its time to ask the LAPD to stop harassing cyclists and pedestrians and do a better job enforcing speeding laws.

Photo: Roland/Flickr

  • Isn’t the federal government talking about LOWERING speed limits to help fuel economy?

  • There aren’t enough police to make enforcement work in a significant proportion of the city – even in Pasadena (we had this same debate last year when we reviewed speed limits here). Traffic calming measures are permanent, and much more effective at getting people to drive slower. However, they cost money, whereas ineffectual enforcement that allows speed limits to creep upwards so that police can continue using radar, generates revenue. Additionally, many residents come out against speed bumps and other physical changes to their residential streets that would reduce speeds (though of course, everyone is for having them on somebody else’s streets…). So, it’s a political problem. Everyone wants other people to magically stop driving fast, but is themself unwilling to pay for or accept the changes in the road that would actually effect the slower driving (and, quite possibly, they still want to be able to drive fast too).

  • The LADOT is following a manual put together by the California Transportation Department called the “MUTCD”. Engineers can recommend slower speed limits, using their professional discretion. If anyone takes them to court over the issue – here is what they can use to protect themselves. As it is, the LADOT reports to raise speed limits barely mentioned residential densities, and did not discuss bicycle or pedestrian safety at all.

    The MUTCD states the following:

    When qualifying an appropriate speed limit, local authorities may also consider all of the following findings:
    Residential density, if any of the following conditions exist on the particular portion of highway and the property contiguous thereto, other than a business district:
    a. Upon one side of the highway, within 0.4 km (0.25 mi), the contiguous property fronting thereon is occupied by 13 or more separate dwelling houses or business structures.
    b. Upon both sides of the highway, collectively, within a distance of 0.4 km (0.25 mi) the contiguous property fronting thereon is occupied by 16 or more separate dwelling houses or business structures.
    c. The portion of highway is larger than 0.4 km (0.25 mi) but has the ratio of separate dwelling houses or business structures to the length of the highway described in either subparagraph a or b.
    2. Pedestrian and bicyclist safety.

  • The issue is not the MUTCD, it is California’s anti speed trap law (CVC 40802), as governed by case law in People v. Goulet (13 Cal.App.4th Supp. 1). Basically, California’s anti speed trap law was enacted after towns like West Covina were setting low speed limits (along US 70, Garvey Avenue at the time) to raise revenue. Therefore, to have the speed limit be enforcable AT ALL (note that in Goulet, the defendant was traveling at 52 in a 35, when the 85th percentile was at 48, which would have warranted a speed limit of 50… meaning that Goulet would have broken the law anyway), the speed limit has to be higher. Thus, the only way to reduce speed limits is to lower the 85th percentile speed. The ways to do this are through signal timing (where you synchronize signals to encourage a certain speed and punish those who travel too fast with red lights) or by traffic calming measures. (A sneaky way some jurisdictions do it is by sticking a radar gun next to the speed detectors, which are generally either traffic loops or two parallel rubber hoses. This biases the speed as folks with radar detectors naturally slow down.) Or, if you really want, try to put together a petition to repeal the speed trap law and watch as the 90% of Californians who drive crush that measure.

  • Tom Rubin

    First, “MUTCD” is the Manual on Uniform Traffic Control Devices,” which is the FEDERAL, not State of California, standard — although, of course, California follows the Federal requirements.

    There is a huge amount of research, going back decades (for example, try the Institute of Transportation Engineers web site) that shows that, in most situations, the way to set the speed limits is to do a study of the speeds that drivers are traveling and set the speed limit at the 85th percentile “free flow” speed — that is, the speed that people are traveling without restrictions. The concept is extremely difficult for many people to accept, but it is based on: (1)most people know what the safe speed of travel is for the road they are on, (2) it is not so much SPEED that kills, but VARIATION in speed — the more uniformity of speed of travel on a road, the better, and (3) most people will drive at the speed they feel comfortable, regardless of the posted speed limit, and no feasible amount of enforcement will change this. In fact, when freeway speed limits were raised after the repeal of the Congressional mandates for 55 mph, fatalities dropped. (When the speed limits were lowered to 55 mph after the 1973 gas shortage, there WAS a drop in highway fatalities that was widely heralded — and still in, in some quarters — but the definative analyses done by the late Charles Lave of UC-Irvine and others showed that the fatality reduction was caused by the high price of gas and shortage of supply, which led to a decrease in vehicle miles traveled, and it was the VMT reduction that produced the fatality downturn.)

    There are, of course, exceptions to this general rule, and “UBRAYJ2” lists the most prominent. However, these exceptions need to be studied and applied in a non-biased manner by experienced professionals applying their experience and judgement, NOT as universal ways to declare a need for lower speed limits because “we KNOW it isn’t safe to drive faster than this number.” If there is an attempt to apply these exceptions in an inappropriate manner, the result will be speed limits that are improperly set too low — and, therefore, at less than optimum safety.

    For example, on I-5 between the Bay Area and Los Angeles in the Central Valley, where the speed limit is posted at 70 mph, the drivers who are doing 80 mph (which is BELOW the 85th percentile speed), ten mph over the posted speed limit, are far less likely to cause or be in a collision than those doing 60 mph, ten mph under.

    One of the problems with setting speed limits too low is that people learn very quickly that speed limits are not properly set and, therefore, there is no safety reason to pay attention to them. As a result, many American motorists tend to ignore ALL speed limit and many other safety signs on the road. By pertending that the speed limit must be set lower for public safety, what we have done instead is to teach our drivers to ignore ALL safety warnings as unrealistic. This can pose major problems when, for example, someone who is used to seeing speed limits on highway turns that are set 10-15 mph under the actual safe speed goes to a state that sets such limits AT the actual safe speed.

    “Traffic calming” — aka, “driver enraging” — is a mixed bag of things, but there really isn’t a lot that makes it appear that there is any improvement in traffic safety in many applications. In fact, there is considerable question if there is a net improvement in overall public health at all, as the extra time required for emergy vehicles to transition through speed bumps and the like can have great negatives, particularly — but not only — for parametics responding to emergencies like heart attacks, where a minute lost can easily mean a life lost. (That said, if I was the father of an nine-year old riding a bike on a residential street used as a short-cut by people barreling through narrow streets with cars parked on both sides at 45 mph, well, you know, I think I just might want SOMEBODY to do SOMETHING.)

    I am most certainly not saying that all roads should be treated like the Daytona speedway; clearly, this is not acceptable. In an ideal situation, there will be sufficient capacity on freeways and arterials to allow the vast majority of longer trips to take place there at safe, relatively high, speeds — and for local streets, particularly residential ones, to be designed for only short trips by people who have business in the area and are not passing through. Obviously, for large parts of our urban areas and street grid, we are way past the chance of this happening.

    What we DO need to do now is to recognize the real-world dynamics of what is going on and to recognize that trying to mandate unrealistically low speed limits is extremely counterproductive; we need to design urban areas, including roads, with an understanding of how the world really works, and try to change the urban environment to conform to human behavior — because trying to do the reverse just doesn’t work out very well.

  • I think Tom makes some interesting points, but I’d like to address the core of his argument which I believe to be:

    “(1)most people know what the safe speed of travel is for the road they are on, (2) it is not so much SPEED that kills, but VARIATION in speed — the more uniformity of speed of travel on a road, the better, and (3) most people will drive at the speed they feel comfortable, regardless of the posted speed limit, and no feasible amount of enforcement will change this.”

    If we accept this as true, and we find that the vast majority of people are exceeding the posted speed limit on a given stretch of roadway, then we have two choices: raise the speed limit or change the nature of the street in such a way that 85% of the people perceive the safe speed to be the posted speed limit, i.e. traffic calming. I will grant that traffic calming is not appropriate for interstate highways and urban freeways if Tom will grant that raising the speed limit is not appropriate on residential side streets where 9-year-olds are often found riding bicycles (which he does).

    The question then becomes what to do with the middle ground: arterials, major streets, etc. It happens to be my opinion that we have generally erred in favor of facilitating increased speeds on surface streets as against the quality of life for people who live, work, shop, maintain businesses, commune with neighbors, exercise, etc. on these streets, as well as bicyclists and pedestrians. In other words, the street functions both as a place in and of itself, as well as a means of travel between places, and we have to consider both functions in deciding how it should be designed.

    The problem with the current approach is that we are allowing one particular issue — LAPD’s ability to do radar enforcement — to trump all other considerations of how we might find the appropriate balance between the two functions alluded to above, and we have no process that would provide a mechanism to let the community have a voice in making that decision.

  • I think LADOT needs to start thinking about traffic calming measures as part of the toolbox of treatments one would use regarding traffic speed. It seems to me that they are just following standards and codes without using other tools to deal with various complex and dynamic situations.

    One of the issues is that LADOT sends just a small amount of their staff to trainings on pedestrian and bicycle issues. Many of these trainings are local and are free to LADOT staff. We just had two Federal Highway Administration trainings in the last month, in Santa Monica and Long Beach, free of charge and the LADOT representation was woefully inadequate.

    If anything, many of these documents are online:


    It is extremely easy for people to access this information.

    I just attended the Pro-Walk/Pro-Bike Conference in Seattle, which is a national conference for transportation professionals to learn about the latest in bicycle and pedestrian planning and engineering, and there were only a few people from the Los Angeles area.

    It’s time that our public officials learn what the latest technology and treatments are, and use them to make our city a safer place for bicycles and pedestrians.

  • Pesach kremen

    Pedestrians, bicyclists, and transit users have more of a right to use the streets than polluting cars.  The safety of the neighboirhood must come first


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