Five dangerous traffic incidents including vehicle retrograding

parking

turning round

reversing

and changing lanes are studied.Object detection

vehicle tracking

incident apprehension and description are used to detect incident automatically based on video. The great emphasis is placed on analyses and researches of the vehicles tracking trajectory. Complicated vehicle trajectory is separated into four elements: ahead

backward

stop

and left or right; then vehicle behavior model is built to analyze vehicles motion based on them. Finally

reasonable algorithms to detect above five traffic incidents are proposed. Experiments show that the normal and the abnormal vehicles can be distinguished

and the five traffic incidents can be detected quickly and effectively by the algorithms.