Detecting and positioning overtaking vehicles using 1D optical flow

We are concerned with the problem of detecting an overtaking vehicle using a single camera mounted behind the ego-vehicle windscreen. The proposed solution makes use of 1D optical flow evaluated along lines parallel to the motion of the overtaking vehicles. The 1D optical flow is computed by tracking features along these lines. Based on these features, the position of the overtaking vehicle can also be estimated. The proposed solution has been implemented and tested in real time with promising results. The video data was recorded during test drives in normal traffic conditions in Sweden and Germany.