AccuTracking

Is it normal for the GPS locations to wander? Whiile the car is parked, the position tends to wander around, as does the elevation. At times, it even says the car was moving 1 -3 mph. Is this part of the built-in innaccuracy the government puts in domestic GPS?

Thanks, my son was going 80 then this morning, and he has some "splaining to do". I want to be sure if I get on his back, the speed readout is accurate.

Can anyone tell me how accurate, in general, the speed (mph) is? This system is for keeping tabs on teenagers, and if they break the speed limit, according to Accutracking, it has to be reasonably close or I can not call them on it. I realize altitude can be way off, and location can be within hundr...