While there is no perfectly clear answer to this question, bicycling information that is provided by the Virginia Department of Transportation (“VDOT”), provides some guidance. VDOT indicates that in general, bicyclists are obligated “to ride as close as safely practicable to the right curb or edge of the roadway”. This indicates that there is a preference for all cyclists to ride in a single-file line. However, exceptions to this preference are allowed when the bicyclist is passing another vehicle proceeding in the same direction.
In addition, that same information states that, “bicyclists cannot ride more than two or more abreast on highways”, and that when riding two abreast, they cannot impede the flow of traffic. This information seems to indicate that it is generally okay to ride two abreast, even when not passing. However, cyclists should move into single file when another vehicle is approaching from behind. This rule does not apply when the bicyclists are riding on a bike path or a lane specifically set aside for bikers. These general guidelines are based on Virginia state laws on bicycling. Other sources, such as Sharing the Road in Virginia, back up these general guidelines, also telling cyclists to:
- stay as far right as possible,
- to not ride more than 2-abreast, and
- to ride single file when moving slower than motor vehicle traffic.
All of this taken together seems to indicate that there is a preference for single-file riding and an out-right ban on riding more than two people side-by-side. Riding two-abreast is definitely permitted when passing, and may be allowed in other circumstances.