1. A computer-implemented method for determining the speed of a motor vehicle in a vehicle speed detection system, the method comprising: receiving a plurality of images of a motor vehicle traveling on a road, each of the images being separated in time by a known interval; determining, for each of at least two of the images, a point of contact where a same tire of the vehicle contacts a surface of the road based, in part, on one or more identified features of the vehicle in one or more of the plurality of images; and using the points of contact and the time interval separations to calculate a speed at which the vehicle is traveling on the road.