Lane Splitting

I commute to work on my motorcycle. Since I drive into San Francisco each day, the traffic can be, and often is bumper to bumper (especially bad Tuesday around 8AM). In California, lane splitting on a motorcycle in not illegal. According to the California Highway Patrol's website:

"Can motorcycle riders "split" lanes and ride between other vehicles?
Lane splitting by motorcycles is permissible but must be done in a safe and prudent manner."

Reader please heed: Lane splitting can be dangerous to your health
Cars are generally not expecting bikes to be zipping past them at 10 - 15x their relative speed on the freeway. I have been cut-off, turned into and blocked on several occasions. I'm not sure it was deliberate or just being unaware. Either way - it's dangerous.


Ways I found to make splitting less dangerous:

1. Ride like your invisible - I grew up in San Francisco and rode my bicycle everywhere, day/night rain or shine until I finally purchased a car when I was 26 years old for work outside the city. My rule for riding was, "ride like I was invisible". I would assume nobody could see me and drove very, very defensively in city traffic.
2. Scrutinize each car you pass as a threat - On my bicycle when I was passing cars, parked in parallel, I tried to look through each cars back window, or/and each side view mirror for a driver. If there was a driver in the car, I assumed they were going to open their door into me and gave them a wider berth (or slowed down for an potential emergency stop). On my motorcycle I do the same when traveling next to parallel parked cars: slow down and look for drivers in each car. If there is a driver, prepare to brake and give them a wide berth moving farther than the arc an opening door would be.
   
3. Be seen - I wear a bright yellow suit by Olympia Phantom Suit. I'm often the brunt of jokes, "big banana man", "CalTrans guy" even mocked by a guy on a Vespa in the city but it helps with safety. It increases my visibility in both day and night as well as keeping me dry in winter. Both my motorcycles have lots of 3M reflective tape all over them to increase their visibility.
4. Slow down - Some guys split at 50-60 MPH. This is just a death wish; it gives very little time to emergency brake, or find an outlet if cut-off. I split at around 30 MPH. If another rider queues up behind me, I pull over let them by. I then look for another biker that might be coming down the split lane, and if clear, head back into the split lane. Repeat as necessary. The fact is that when I usually split, traffic is pretty much a parking lot screeching along at 2-3 MPH. My relative speed combined with my visibility gives drivers fair warning I'm coming through so there are few surprises as I approach and pass them.
5. Some freeway lanes are narrow - During my commute there are a couple of stretches where the freeway lanes narrow and the split lane is too narrow for a safe split at any speed. Normally most considerate drivers will move over a bit if they know you're coming. When moving slowly through the split lane I feel it's important to be considerate of other motorcyclists which may still want to barrel though it. Ergo: I periodically scan my mirrors for other bikers and if getting close move over to let them roll through.
   

Dealing with jerks in cages:
Sometimes I encounter the pick-up with extra-wide mirrors or the shiny BMW that is blocking the split lane with their car and/or mirrors. I try to identify these vehicles as early as possible and if necessary to, slow, signal and transition into another lane. Switching lanes can increase risk, since other drivers are expecting consistency. I believe driving consistently is important since it helps our brain calculate when an object, at a fixed velocity will arrive. Our brains do a great job of this calculation but the accuracy is based on consistency. Changing your line or speed influences the effectiveness of this mental calculation. If I need to move to another lane I always use my turn signals and try and clearly communicate my intentions to other drivers. Sometimes the driver is on-the-phone, doing their make-up or just spaced in traffic. Either way communicate your intentions clearly with by signaling, and slowing-down, before changing lanes.

Splitting lanes is a fact-of-life in the daily Bay Area commute for a motorcyclist. Before attempting this you need to have a very good feel for your motorcycle: be able to emergency stop well and be prepared to do double-duty with defensive driving. Slow-down, be very observant and consistent in your driving and you'll save some time in traffic and come out the other side.

Be safe.