Skidding - poor traction, i.e. alluvial sands in corners. Insufficient speed - lost balance, i.e. couldn't get foot on ground soon enough. Cyclist fails to yield to cross traffic - going through stoplight or past stop sign. Cycling wrong way - a very unpredictable behaviour. Cyclist fails to yield changing lanes - didn't negotiate to change lanes.
Motorist turns left - first most common motorist caused collision, see below.
Cycling on sidewalk - a common cause of children injury and death. Children don't understand that every driveway is an intersection and how to approach them cautiously. Motorist turns left - motorist travelling in opposite direction collides in intersection. Motorist turns right - motorist passes cyclist and turns right in intersection. Motorist restarts - motorist stops at side road, restarts and collides in intersection.