For what condition would a bicyclist avoid riding two abreast in traffic?

A bicyclist should avoid riding two abreast in traffic primarily when the lane is of substandard length. In scenarios where the lane is narrow, it can be challenging for motor vehicles to safely pass cyclists. Riding two abreast can further reduce the available space on the road, increasing the risk of a collision or creating dangerous situations for both the cyclists and nearby vehicles. It is important for cyclists to prioritize safety and maintain a position that allows for safe passage for all road users, particularly in limited space conditions.

While having ample space on the road might actually encourage riding two abreast, it may not be necessary when riding with a friend or even while riding downhill, as these conditions do not inherently create risk for hazards. Thus, awareness of lane width and the surrounding environment is essential for maintaining proper safety while cycling on busy roads.