I'd actually feel more comfortable around "zoomer" than "crawler". It sounds like zoomer is a leadfoot, but not inattentive. Crawler strikes me as someone who likely isn't paying very much attention. Given that it's 5:00am, I'd rather have someone at least looking for me at intersections than someone just glancing and rolling through because of the false sense of security 5:00 am might create. I also doubt he's hitting 50mph for any sustained period of time in a residential neighborhood.

Not that either is safe.