Any satellite with the resolution to image cars and determine their speed would have to be in low Earth orbit. From there, it would only be within the field of view of a checkpoint for a few minutes a day. They have a fairly narrow field of view, too. There aren't very many of those satellites, so the odds are against a satellite just happening to be within view of the checkpoint (and just happening to be looking in that direction) just as her car approached are pretty slim.

Odds are much greater that any such video would come from a UAV or similar airborne platform. Those vehicles can dwell over a given area for hours at a time.