I’m a follow-the-rules bicyclist, but I think Phil is wrong that scofflawism is what causes unpredictability (though I agree 100% that unpredictability is the problem). Bicyclists are “unpredictable” because most drivers have little relative experience both with bicyclists and as bicyclists. They know how to deal with bad drivers (who may blast thru a new red light, or cut an immediate left on a new green), but not so much bicyclists because there are relatively less of them than cars. Also because few drivers are bikers, they don’t know why a bicyclist may try to take a lane if they see you trying to aggressively pass them coming to an intersection (to stop a potential right hook), for example. A lot of “unpredictable” bicycle actions are actually defensive bicycling; becoming a clear target is sometimes the best way to avoid becoming a victim (“they can’t deny they didn’t see me”)