There are a lot of signs on the road that say "Speed checked by radar".  I understand this.  There's a rule, and in order to enforce the rule, police officers use radar.  But my question is, when is this fact not true?  In other words, are there roads where the speed limit isn't checked by radar?  Or is there some other sort of magical device that's used to measure speed besides a radar gun?  If speed is always checked by radar, there's really no need for the sign any more than there's a need for a sign that says, "Continue moving forward". #travel