Yesterday I accidentally went through a 30 mph speed camera at 40 mph and you know what? I didn't get flashed, must have been my lucky day. Don't try it though ... absolutely hate speed camera's, they're everywhere and what's the point driving if you can't go fast?
my brothers theory is that you can go upto 39mph at a 30mph speed camera and it wont flash. I haven't been flashed yet and there's about 5 speed camera's on the road between my house and my mums.
for gatso speed cameras the tolerance is 10%+2mph.
therefore for 30mph you can get away with 30+3+2 = 35mph.
And then your speedo is never calibrated exactly to 3omph, especially if you've got alloys with wide tyres on (like me hehe.)For example mine reads about 35mph when im actually doing 30mph.
So if you take into account your gatso and speedo toerances, you can probabaly get away at 40mph nil problemo!