|Many bicyclists willingly or naively shoot themselves in the foot on the subject of
riding side by side. I have often heard the admonition "ride single file" in
bicycle clubs' pre-ride safety speeches. This admonition is at best an oversimplification.
It is out of step with the reality of bicycling and with bicyclists' best interests.
Riding side by side has many advantages for bicyclists.
Riding side by side is by far the most practical way that bicyclists can share information with one another, beyond the very limited communication that is possible with hand signals. Riding side by side is essential to give safety advice or directions, for example: "don't go down that road, there is a house with really mean dogs running loose." I frequently must give instruction to students in my Effective Cycling classes while riding next to them.
Without side-by-side riding, a group bicycle ride becomes a silent procession or a shouting match, rather than a social event. Do we really want to put this damper on bicycle club riding? Bicycle club members learn from each other as they ride together, and their accident rate is 5 times lower than the average for college-affiliated adults, both because of side by side riding and in spite of it. Bicyclists at the rear of a riding group call out "car back" and, in the clubs I ride with, a bicyclist who will not "single up" gets a lot of flak from riding companions.
Only one state (Nebraska) requires single-file riding at all times, and a few others (Colorado, Hawaii and Montana) require it except under special circumstances The most common rule allows riding two abreast unless traffic is impeded, while New York and Viginia require riding single file while being overtaken, even if riding two abreast would not impede overtaking. More details are on Paul Schimek's Web site, though last I saw, the information aobut Massachusetts was out of date -- riding two abreast is now permitted.
Any single-file law has serious conceptual problems. First of all, it is unnecessary. Riding side by side is illegal in every state when it unnecessarily impedes traffic. Why should bicyclists have to ride single file if they are not impeding traffic? If you know that no motorists are waiting behind you to pass, what's the point of making room for the motorists who are not there? If they have a clear lane in which to overtake, why single up?
Not only that, side by side riding is completely unavoidable, since one bicyclist can only overtake others by riding side by side with them. For these reasons, laws prohibiting riding side by side are unnecessary, unreasonably restrictive and unenforceable.
If a motorist collides with bicyclists who are riding side by side, and a single file law applies, the presumption of negligence can be shifted to the bicyclists - to both or all of them, even though only one of them may have made a decision to overtake, and even though overtaking is, last I heard, legal!
On any road where motorists can use the next lane to overtake and can see the bicyclists from far enough behind to merge around them, riding side by side inconveniences nobody and is reasonably safe. Bicyclists who use a rear-view mirror, as I do, can easily check for vehicles approaching from the rear. We just merge back into a single line when we see a vehicle that needs to and safely can share a lane with us. Bicyclists who don't use a mirror can't be quite as free about riding side by side, but in either case, the correct decision is only a question of good judgment.
Riding side by side is indeed hazardous when sight lines are limited (just past a hillcrest, or on a curving road lined with vegetation or walls). Still, under these conditions, the overtaking motorist who strikes a bicyclist was clearly exceeding a safe and reasonable speed, or inattentive: this motorist would also have been unable to avoid a pedestrian crossing the road, a mail truck stopped at a mailbox, or a slow farm tractor.
I certainly don't recommend riding side by side for children (except perhaps on very quiet neighborhood streets), and it is sometimes abused even by bicycle club members. But that doesn't mean that it should be illegal, or universally condemned. To summarize, I advocate repeal of laws against side-by-side riding, enforcement against bicyclists who unnecessarily impede traffic, instruction of adults in safe and courteous riding, and discouragement of side-by-side riding by children.