In radar theory there is a speed at which contacts disappear. It's called the radar Blind Speed and every radar has a specific blind speed. It's a case of knowing the exact fequency of the radar and the theory goes that if you are travelling on a radial bearing to a radar (ie straight towards it or away from it) and travelling at half the wave length or multiples of it in the pulse interval then the target will not appear on the screen. Here is the real formula for it:
vm =
m 
f /102, where
v is the blind speed in knots,
m is the multiple of the radar pulse repetition rate and the number of the blind speed, namely a positive integer, 1, 2, 3, 4, . . ., for the first, second, third, fourth, and so on, blind speed,
is the wavelength of the illuminating radar in centimeters;
f is the Transmitter pulse repetition rate in pps (pulses per second); and the 102 is a units conversion factor.
Or something like that - it's years since I did that sort of thing practically but it really did work and allowed us to do certain other things. Unfortunately, the sort of radars we went up against meant doing about 240 knots (about 275 mph) but it would be interesting to know what the speed camera radars operate use.
A cunning plan ?