Tuesday, April 26, 2011

SB910: 3 foot passing zone

The California State Senate is considering SB910, the latest in a long-running series of bills requiring a minimum passing margin for cyclists. The text of the bill is here.

The key text:

21750.1. (a) (1) The driver of a motor vehicle overtaking a bicycle proceeding in the same direction shall pass to the left at a safe distance, at a minimum clearance of three feet, at a speed not exceeding 15 miles per hour faster than the speed of the bicycle, without interfering with the safe operation of the overtaken bicycle.

I'm a huge fan of a 3 foot passing margin. It really changes nothing, since any rational observer would conclude passing with less than a three foot margin is unsafe, and it's illegal to pass at an unsafe distance. But this codifies that less than 3 feet is de facto unsafe, removing the burden to prove it. For example, presently a driver could pass with a two-foot margin, hit a cyclist, then claim it was the cyclist's fault for veering to the left. The 3-foot margin gives the cyclist some breathing room.

Of course, it could be argued if a 3-foot margin is necessary to deal with unforseen circumstances, like the cyclist hitting an object on the road and swerving two feet to the left, then the law would actually require an anticipated 6-foot margin, to give the driver a 3 foot margin to avoid the 3-foot margin and therefore a violation. But this is perhaps being picky.

However, what I don't like about this bill is the 15 mph speed difference. It's simply impractical. Bikes are allowed on certain shoulders of I280, for example. Shall all passing traffic slow to 25 mph to accommodate a 10 mph cyclist? The fatal flaw is that the safe passing speed is actually a function of the gap. Perhaps with a 3 foot margin, a 15 mph differential is recommended. But then with a 4 foot gap, the speed can be higher, and with a 5 foot gap, higher still. The law doesn't recognize this: it simply places a 15 mph speed differential limit, even if the car is all the way into the opposite lane.

So I view this presently as bad legislation. I have been told by a member of the California Bicycle Coalition that an attempt will be made to clean this up. Nobody seems to know, I was told, how that 15 mph differential item got into the bill. Given that it's been there for several months, I don't know what's taken so long. It's so obviously flawed.

I really hope this one gets cleaned up and sent through. The arguments against it, that a 3-foot passing requirement will unduly slow traffic, are absurd because they imply, without explicitly stating, that it's acceptable to pass a cyclist closer. As it stands, it's simply too hard to prove a pass was "unsafe". With this bill you'll simply need to prove the pass was closer than the 3-foot margin.

No comments: