Originally Posted by
squirtdad
In California, cyclists may legally ride two or more abreast, as long as they are traveling at the "normal speed of traffic," or if they are traveling in a lane that is too narrow to safely share with a motor vehicle.
However, if the cyclists are not traveling at the "normal speed of traffic," and the lane is wide enough to safely share with a motor vehicle, then the cyclists must ride single file.
Indeed, this was the whole basis of the legality of the situation concerning the cyclists and the Brentwood Doctor that slammed on his brakes in front of the cyclists, who were two abreast.
http://latimesblogs.latimes.com/lano...sentenced.html