Speed Estimation Using a Moving Camera, Presumably Uncalibrated Camera

Hi, I am a Mechatronics student and was thinking about an innovation as my final year project and the speed estimation through camera image processing caught my attention, but I need some advice or opinions on the topic, so for those in the field, could you please provide me some of your advice; will it be too tough for Degree students? Have anybody done research in this field before? Sorry if this post doesn't belong here, feel free to direct me to the appropriate sections and thanks in advance to those who reply.

Btw, I was thinking of mounting the camera and the components to a moving car and using it as a sort of safety feature to notify drivers when potential rear-on collisions might happen, thus the 'moving camera' part on the title of the thread.

You may be better off with a ultra sound doppler device.
https://dspace.library.cornell.edu/retrieve/264/PM+01+007.pdf

Just thought of that as well, but the application part may still change. Still undecided on the exact application to venture. Thanks for the feedback.