Man vs. speed gun

Observed today:
Periodically law enforcement here put up one of those speed gun type devices- you know it has a big screen and tells you how fast you were going as you approach. I take it they do this in areas where people commonly drive too fast, hoping if you see how much you are violating the speed limit, you'll mend your ways.
A few times I have seen this on one side of the main street here, I'm guessing because people tend to drive too quickly and come speeding through the curve in the road. There are often buses, both school buses for kids and Cyride, the public bus, stopping on this road; and there was a Boys and Girls Club, before it got flooded.

Today the radar speed gun was on the OTHER side of the road, just up from the bus stop. As I was walking over to the stop to wait for the bus, I saw 2 guys: one was running down the street & the other watching (yes, Dumb and Dumber here) to see if the radar gun would pick up his running speed! Um aside from the fact that they are now RUNNING in the road, into oncoming traffic, which seems a little bit of a bad idea, I kind of don't think that these speed guns actually measure PEOPLE speed.
I'm not entirely sure of this but I get that feeling. Plus this explanation on How Stuff works website tells me, " A laser speed gun shoots a very short burst of infrared laser light and then waits for it to reflect off the vehicle. "
I could be wrong on this. But anyway... running in the middle of a busy road to try to see if it will measure your running speed, just doesn't seem like the safest or sanest idea.