Just to close the loop for anyone finding this thread in the future.
The OP asked if you could also use this to see people at night and we responded that the answer is no due to the fast shutters we have to run in order to capture a fast moving plate AND take advantage of the reflective properties of a plate.
Here is someone walking past my LPR camera in the middle of the night with a reflective vest on. As you can see, all you see is the reflective stripes. Had he not been wearing that, the camera wouldn't even have picked him up.