I happened to pull up behind an Arizona Highway Patrol photo enforcement van Tuesday and thankfully had my camera next to me and was able to snap a photo in short order.
I'm not sure how long I actually had while in the Photo Enforcement zone to comply and take a picture... Of course I also made sure I had a safe film speed for the road conditions, no blurry focus, no red eyes, and certainly no flashing.
Arizona Department of Public Safety now has 42 of these vans snapping pictures and issuing tickets by mail to excessive speeders on state highways. For those of us with digital cameras, and I know this goes against the grain, its probably best to have your ISO speed at 200 or less when snapping a pic in an enforcement zone... Be sure to shutter like the rest of us when you get surprised by one of these zones. *smile*
[I won't get into the pros/cons of these camera enforcement zones, both mobile and fixed location. There are definitely some pluses and minuses.]