I think my original post was a little confusing. The video is not from my LPR camera, it's from one of my "driveway cams".
Yes, you guys are correct, the missing 15 seconds is due to no motion. That camera was never intended to pick up activity 160 feet down the street, most of the year there are leaves on the trees which would block the view down the street.
After reading the comments on my post I'll most likely go to full time recording. thanks for the feedback.