It was unofficially allowed the 17mo I lived out there '95-96.

Doing it at a stoplight is called "filtering" where the bikes all scoot up to the front between cars. When the light turns green, they're all first across the intersection and out of everyone's way.

This is a low-speed maneuver and generally safe.

Also generally safe is working your way between cars during a traffic jam. Some car drivers get their nose in a twist because "someone's getting ahead of me!" -- well buttercup, go get a bike. The weather's nice (usually) and you're only driving yourself to work and back, so you don't particularly need a car.

On the other hand, splitting lanes on freeways at speed is certainly more risky. I didn't try that, I never felt the need to give Death a kiss on the lips.