A vehicle speed determination system and method receive image data of a field of view of a camera operably disposed onboard a vehicle. A speed and/or heading of the vehicle are determined as the vehicle is moving based at least in part on one or more differences in the image data. In one aspect, pixel intensities in different images or frames may be examined to identify one or more features of interest in the images or frames. Movement of the one or more features of interest in the images or frames is correlated to movement of the vehicle along the route, and the time difference between when the images or frames are obtained can be used to determine the vehicle speed.