The width of bike paths and to a lesser degree other qualitative aspects of bicycle provisions such as the surface quality are a factor in bike-bike accidents. A greater width creates an additional margin of safety so other (behavioural) factors cause accidents less easily. And a curb without a difference in height with the road surface creates room for evasive action. The existence of two-way bike/moped paths is a major factor in some types of accidents, in particular collisions between cyclists and moped riders when passing and overtaking.