Here at MO, we are strong proponents of lane splitting. Not a day goes by in which we don’t filter between the lines of slower moving or stopped cars. In the process, we’re also easing congestion and protecting ourselves from being rear-ended by distracted drivers. So, naturally, we were excited last year when we heard of California bill AB 51 was making the rounds in an effort to codify the act of lane splitting by giving it a set of clear rules for riders to follow. One of the primary benefits of the rules would be that they would make it possible to educate the driving public about lane splitting.

AB51 To Formally Legalize Lane-Splitting

Hallelujah! The AMA Endorses Lane Splitting

The Truth About Lane-Splitting

Skidmarks – Splitting Headache

Unfortunately, the bill was pulled last July at the request of its author, California Assemblyman Bill Quirk, because of fears that it would not pass. Since that time, Quirk has worked on changing the language of the bill to a form that will improve its chance of passing. According to, an organization devoted to promoting lane splitting, the wording has changed to a much less specific recipe for legal lane splitting to a more generalized one. The result is a bill that maintains lane splitting’s legality by virtue of not being explicitly illegal while giving the CHP the option of developing and distributing educational guidelines for riders and the driving public to better understand safe lane splitting.

AB 51 new text

A sample of how the updated AB 51 text will read, produced by

In a mockup of the amended version of AB 51 produced by, the specifics of the top speed and the speed differential between the motorcycle and other traffic have been removed. In their place, the mandate for CHP to create guidelines to educate the public is inserted: “The California Department of Highway Patrol may develop educational guidelines relating to lane splitting in a manner that would ensure the safety of the motorcyclist and the drivers and passengers of the surrounding vehicles.”

Additionally, the agencies that the CHP is to consult in developing the guidelines includes not only the Department of Motor Vehicles, the Department of Transportation, and the Office of Traffic Safety, but it also lists the requirement of consulting with a “motorcycle organization focused on motorcyclist safety.” So, we assume the organization selected would be either the AMA or the MSF, giving actual motorcyclists an active say in the development of lane splitting guidelines – which is very good news!

These changes were scheduled to be submitted to committee yesterday, May 31, 2016, but at the time of publication, the bill’s page on the California Legislative Information website had not been updated. Interested parties can track the progress of the bill there. California residents who want to contact their representative can search here. Those who want to contact Assemblyman Quirk’s office can visit his web site.

  • Surj from here. Just to clarify, I didn’t “produce” that mockup—from the article you quote above: “Here’s the bill mockup from Quirk’s office…”

    The bill has now been amended with the updated language:

    • Old MOron

      Hey Surj, thanks for stopping by, and thanks for the link. Did you work with Quirk to craft this bill? If yes, then I have a couple of questions, please:

      1. The text of this bill does nothing more than invite the CHP to write and publish guidelines for lane splitting. Do you expect guidelines to make splitting safer? Or are you more interested in having a written law on your side when faced with objecting cagers? Why do you invite more regulation on our heads?

      2. According to CVC 400, referenced in the bill:
      “A ‘motorcycle’ is a motor vehicle having a seat or saddle for the use of the rider, designed to travel on not more than three wheels in contact with the ground.”
      Why does the bill specifically say “that has two wheels in contact with the ground”? Have you no love for the MP3?
      I suppose one can affirm that the MP3, indeed, has two wheels on the ground. Is it wheelies you aim to forbid? I think there are plenty of laws to do that already? What gives?

      Thanks for your consideration.

      • Yes, I was part of a group including reps from the AMA, BARF, and others as well as Tom Rice of Berkeley SafeTREC that met with Quirk last year and worked on the original versions of the bill. However, this latest version as developed outside of that group, over the course of the last year, based on his meetings with other folks in government in an attempt to craft a bill that would pass. In general, we’re all happier with this language than the previous language—it’s more general, and re-opens the door for the CHP to educate riders and drivers.

        It you look at the research done by OTS in their lane share surveys (available with many other documents it sounds like you’d do well to read here:, the numbers were improving in the couple years after the guidelines were originally published. Drivers were more aware of lane splitting, riders were splitting a bit slower. So yes, I think the return of the guidelines will make riders safer, and there’s evidence to that effect.

        As to inviting more regulation on our heads, while I’m tempted to laugh that uninformed and ridiculous question off, I’ll humor you with an answer. The original CHP guidelines were created as the result of years of work in response to a move by people within the government at the time (DMV, specifically) to ban splitting. There have been other attempts to regulate since, including Senator Beall’s SB 350 from 2013 / 2014. Collaborating with a sympathetic legislator to get a favorable bill in place is a preemptive move, not some anti-freedom invitation to more regulation. There’s tons more information on (and elsewhere) that it seems you’d be well served to bone up on.

        On your second point… really? The purpose of this bill is not to redefine what a motorcycle is—existing vehicle code already does that. Forbid wheelies? Surely you jest.

        Remember, things that aren’t illegal (prohibited) are legal. Until there’s a law that say MP3s can’t split, it’s legal.

        • Old MOron

          Dear Surj, I acknowledge that “invite more regulation on our heads” was intended to get a response. I did not imagine it would be so condescending. Nevertheless, I’ll bone up, as you so helpfully suggest, but it will take me a little while, as the material you linked is extensive.

          I did read the abstract to the first article on your page, and I gleaned a few bits of info. “Lane-splitting appears to be a relatively safe motorcycle riding strategy if done in traffic moving at 50 MPH or less and if motorcyclists do not exceed the speed of other vehicles by more than 15 MPH.” And yet the CHP guidelines said, “It is not advisable to lane split when traffic flow is at 30 mph or faster … Travel at a speed that is no more than 10 MPH faster than other traffic”. So while my aversion to more regulation may have been overstated, perhaps it was not unfounded.

          I did not know that the original CHP guidelines were crafted as a defense of lane splitting. This does show them in a new light. Thanks for the info. As for the preemptive legislation, is it really necessary? Is the DMV that close to banning lane splitting?

          As to the second point, yes, my question was and is sincere. Since motorcycles are already defined as including three wheelers, why is it necessary or desirable to specify “having two wheels on the ground” in the bill?

          • Look, I have limited time to spend in discussion with people who use insulting and ignorant accusations like “Why do you invite more regulation on our heads?” and “Is it wheelies you aim to forbid?” You’re asking irrelevant, uniformed questions in that tone and you’re surprised that I’m condescending? If you want to engage in a serious discussion, I’m happy to do that, but I’ll urge you (again) to educate yourself on the matter at hand first, or engage in sincere conversation minus the tomfoolery.

            Guidelines aren’t regulations. So yes, your blanket aversion to regulation remains unfounded. Furthermore, knee-jerk objection to *all* potential legislation *just because* is just as silly as seeking to solve all problems with legislation. If that’s your philosophical bent, there’s no point in continuing this conversation.

            Yes, preemptive legislation is necessary. There are a lot of people that have been working hard on this issue years, rather than hanging around the comments sections of moto-websites. Don’t you think it’s a little presumptuous to helicopter in with a clear lack of background and engage in borderline trolling cloaked in uninformed hypotheticals?

          • Old MOron

            Did I give the impression that I have a blanket aversion to regulation? I don’t. But I do have an aversion to meddling in something that is already legal and working just fine as far as I’m concerned.

            In your first reply you reminded us that lane splitting is legal specifically because it is not prohibited. Yet you have been working on this issue for years? No wonder you don’t have time for uninformed borderline trolls.

            But let me get back to my sense of working just fine. I also looked at the “excellent study of lane splitting in California by James Ouellet” that you provided. It’s a thick dissertation because he’s looking at data from the multiple studies, but one of his principal findings is, “lane splitting crashes appear to be a tiny portion (less than 1%) of the motorcycle accident population.” And his first conclusion: “It is clear that lane-splitting contributes little to the population of motorcycle accidents – less than 1% both in Los Angeles in 1976-77 and a quarter century later and a continent away in Europe in 1999- 2000.” All of this without guidelines. So remind me again why suddenly they’re so urgent.

            Finally, you still haven’t replied to my sincere question. Since motorcycles are already defined as including three wheelers, why is the “two wheels on the ground” language necessary in the bill? I mentioned wheelies and MP3s because that’s all I could think of. But since I helicoptered in so uninformedly, it’s no surprise that I got it wrong, eh? I don’t suppose you care to enlighten us as to why “two wheels on the ground” is in the bill. I’m genuinely curious. You see, I’m going to have to decide on whether to support this bill. Obviously, I’m disinclined to do so, but I’m willing to examine the text and look for a reason to go one way or the other.

            Speaking of text, how come I’m the only one referring to the text of the bill and of the motorcycle safety studies? How come all you’ve done is condescend and call names? Who’s the presumptuous one here?

  • Born to Ride

    I am glad they removed that top speed stipulation, I was worried that it was going to just become another means for CHP to write tickets. I hate bills introduced to improve public awareness that end up giving the government more means of divesting citizens from their hard earned money. I have followed officers (On bikes) on the freeway splitting at speeds upwards of 60 mph in perfect safety. I see no need to enforce another secondary speed limit.