Accident Detection in Python using OpenCV (Payment through easypaisa)

You will have to deliver a program in python that will take a video of traffic feed and and will detect the vehicles in it.. Then it will calculate optical flow of the vehicle.. And the least and the major task will be to detect accident.. when two vehicles collide.. it will detect the collision and will give the notification in form of count or something. GUI is not necessary but extra payment will be made if it's included.. Main focus should be accident detection.. Time limit is till Friday Saturday.. 4000 PKR without GUI.. and 5000 PKR with GUI..