Would California motorcycle lane-splitting rules be hard to enforce?

The California assemblyman who backed off plans last week to put limits on lane-splitting by motorcyclists said his hopes to corral the more extreme forms of the maneuver are far from dead.

It’s just complicated, says Assemblyman Bill Quirk, D-Hayward. (And he knows complicated. He has a Ph.D. in astrophysics.)

Lane-splitting occurs when a motorcyclist cuts between two cars in adjacent lanes to scoot ahead of the crowd. It’s controversial. It’s common. And it’s legal in California, if only by default. State law currently doesn’t address it.

Quirk and his legislative colleagues, including Assemblyman Tom Lackey, R-Palmdale, a former California Highway Patrol officer, are struggling to wordsmith a safety-focused law that will make practical sense in the real world.

They’ve been talking with the CHP, and although Quirk’s office and the CHP are declining to say what they are discussing, it’s clear one tricky hurdle they face is enforceability.

Quirk’s bill, now temporarily shelved, would have limited motorcyclists to splitting at no more than 15 miles per hour faster than the cars they are passing. It also would have prohibited motorcyclists from splitting at speeds above 50. That means if freeway traffic slowed to 35, motorcyclists could cut between cars at up to 50. But anytime freeway traffic is going 50 or faster, motorcyclists would be banned from lane-splitting.

But it’s hard for police to catch up to a speeding lane-splitter, especially if traffic is clogged. An officer in a patrol car is like the cat that can’t squeeze through the hole the mouse just dove through. Officers on motorcycles face the question of their own safety if they choose to chase a lane-splitting cyclist at a high speed.

It also may be hard for officers to measure two speeds at once, that of the motorcyclist and the adjacent drivers.

Quirk appeared to reference those conundrums in an email to The Bee last week.

“There are some concerns about how the provision of the bill will be implemented in real life,” he wrote. “Rather than rushing the bill through the process, I have decided ... to allow for more discussion with stakeholders and resolve those outstanding questions.”

Why not ban lane-splitting altogether? For one, motorcyclists oppose that. Also, a recent state-sponsored UC Berkeley study found that lane-splitting is not necessarily dangerous when done at medium speeds and/or with low speed differentials between cyclists and nearby cars.

Even if enforcement is problematic, state highway safety officials say there’s another good reason for rules. It gives them a launch pad for public awareness campaigns that could help set new norms for behavior on the road, and reduce some of the road rage that surrounds lane-splitting.

You need both, though – enforcement and education – to make a law work.

This story was originally published July 12, 2015 at 2:34 PM with the headline "Would California motorcycle lane-splitting rules be hard to enforce?."