When are bicyclists allowed to ride two abreast in a traffic lane?

Bicyclists are allowed to ride two abreast in a traffic lane when there is sufficient space for vehicles to pass. This situation ensures that the presence of the bicyclists does not impede traffic flow and allows cars to safely navigate around them. Riding two abreast can improve visibility and enhance safety for both cyclists and drivers, as long as the conditions on the road permit it.

In contrast, substandard lanes typically refer to narrow lanes that may not provide enough room for safe passage of both bicycles and vehicles. Riding two abreast in such areas could create hazardous conditions for both the cyclists and the motorists. Other choices such as riding without parked cars or on designated bike paths do not specifically address the criteria of allowing safe passing space, which is crucial for determining whether riding two abreast is permissible.