Any California motorcyclist who’s suffered a lane-splitting accident in the last few months should consider consulting an attorney regarding any legal standing you may have to sue Mr. Kenneth Mandler. Why? Because it was him and his sanctimonious indignation that forced the CHP to retract its Lane-Splitting Guidelines – a safe riding tip sheet that may have helped riders avoid crashing or minimize potential injuries while lane-splitting had it been available.

“By forcing the California Highway Patrol to remove its guidelines, Mr. Mandler and the Office of Administrative Law are denying the public vital safety information,” said Nick Harris, AMA western states representative and a member of the California Motorcyclist Safety Program Advisory Committee, which helped write the guidelines.

Skidmarks – Splitting Headache

“Lane splitting is still allowed, and motorcyclists are still using this long-recognized riding technique to relieve traffic congestion and improve safety,” Haris said. “But now, neither riders nor motorists have a place to turn for authoritative guidelines on the practice.”

Is lane-splitting safe? I posed this question in my Truth About Lane Splitting article one year ago. Because, at the time, no motorcycle safety study had ever concluded with any authority the safety of lane splitting. That has now changed thanks to Thomas Rice and Lara Troszak.


Lending support to a lane-splitting lawsuit against Mr. Mandler is the recently released preliminary report by Rice and Troszak: “Safety implications of lane-splitting among California motorcyclists involved in collisions” conducted by the Safe Transportation Research & Education Center University of California Berkeley. The complete study will be made available at the first of the year (and we’ll fully report the findings then), but the preliminary report has this to say in regards to the CHP Lane-Splitting Guidelines.

“We compared the proportion of collision-involved, lane-splitting  motorcyclists with injury across several body regions by whether the lane-splitting was done in a manner consistent with the former CHP guidelines. The guidelines had recommended that lane-splitting be done only in traffic flowing at 30 mph or less and that the motorcycle speed should exceed the traffic speed by no more than 10 mph. We found that the proportion with each injury type was high when the lane-splitting was consistent with neither recommendation, was lower when it was consistent with one recommendation, and was lower still when it was consistent with both recommendations.

For example the proportion of motorcyclists with head injury was:

  • 6.3% for those lane-splitting consistent with both guideline components.
  • 9.0% for those lane-splitting in traffic flowing faster than 30 mph but exceeding traffic speed by less than 10 mph.
  • 10.7% for those lane-splitting in traffic flowing at 30 mph or less but exceeding the traffic speed by more than 10 mph.
  • 20.5% for those who were lane-splitting in traffic flowing at more than 30 mph and who were exceeding traffic speed by more than 10 mph.

The study also found that motorcyclists who practice lane-splitting were better helmeted and less likely to suffer head injury, torso injury, and fatal injury than other motorcyclists. There were also fewer instances of alcohol consumption or being unlicensed among lane-splitters.

Last year, Mandler petitioned the California Office of Administrative Law claiming the CHP Lane-Spitting Guidelines were  an “underground regulation” that the CHP was unlawfully promoting. The Office of Administrative Law agreed and forced the CHP to remove the guidelines.

Mr. Mandler has the right to oppose lane-splitting. But instead of exercising his rights via the legislative process in an effort to illegalize lane-splitting, he attacked a good-deed effort of the CHP to promote safe and responsible lane-splitting, thus potentially endangering the health and safety of motorcyclists who choose to lane-split. And for that, we think the man ought to hear our voices.

Your lawyer can reach Mr. Mandler at Please be polite.

  • Old MOron

    These guidelines were basically the same thing the CHP has been telling people via the MSF New Rider Course for many, many years.

    Except the part about “only split when cages are going ≤ 30 mph”. That must’ve been added by the officious milksops in the so-called California Motorcyclist Safety Program Advisory Committee.

    • Gabe Ets-Hokin

      The MSF does NOT discuss lane splitting in any of its RiderCourse curriculum. The official word is that any discussion of lane-splitting in class should be steered into a discussion of whether it can be performed within the boundaries of techniques taught in the class (spoiler–it can’t).

      • Old MOron

        Hmm, I suppose this is further work of the officious milksops at CMSPAC. When I took the MSF course, they very clearly and deliberately stated, “This is the official recommendation of the CHP…”

        And Gabe, what do you mean by your spoiler? Are you saying SIPDE is not applicable to lane splitting?

        • Gabe Ets-Hokin

          SIPDE? That’s the old curriculum, phased out in 2002. But it seems just like yesterday, no?

          Also, regardless of when you took the MSF class, there are always RiderCoaches that add “bonus material” that is pulled completely from their own asses. I wasn’t a RiderCoach back them, but I seriously doubt the MSF EVER had anything to say about lane-splitting.

          • Old MOron

            The “bonus material” I got was from a man named Bill at Simi Valley. He was some sort of retired marine. He went around to various schools to make sure they were teaching the material properly. He was very specific: “This is the official CHP recommendation…”

            Now, please explain your spoiler. What’s all this about lane splitting can’t be taught within the boundaries of the course?

          • Tinwoods

            Are not roads required to perform lane-splitting techniques? As far as I understand them, students never venture on actual roads during the MSF safety courses.

          • pcontiman

            cold Tin, Cold.

          • Old MOron

            If I’ve understood Gabe (who seems to like to snark and run) correctly, lane sharing cannot be performed within the boundaries of the techniques taught in class.

            But if the class teaches SIPDE or SEE or whatever they call it now, lane sharing is definitely performed within the boundaries of those techniques.

    • Tinwoods

      And for the tens of thousands of riders out there who did not take the MSF course?

      • Old MOron

        They seem to be doing well enough. No need to slow everybody down to 40 mph.

  • Gabe Ets-Hokin

    Good job outing Mr. Mandler, Tommie! I’m glad you wrote this.

    • Tom Roderick

      Thanks, Gabe. I meant to include a link to your Splitting Headache article, but forgot. That has been remedied.

  • pcontiman

    The letter has been sent.

  • Ferris Argyle

    Amazing brazenness to publish this under the heading “Enjoy imposing your will on others” with no apparent sense of irony.

    These guidelines were removed because the CHP was doing exactly that. CHP Commissioner J. A. Farrow certified that his department would not “issue, use, enforce, or attempt to enforce the public education information”, and The Office of Administrative Law determined that posting the guidelines on the website was “issuing” them.

  • Backroad Bob

    Cunningly written. Bravo!