Originally Posted by
dojj
if they only send you one picture, as how they can proove how fast you were going without another picture time stamped to use as a gauge to see how much distance you covered
With the camera vans you only get the pictures if you ask for the evidence. The first has the instantaneous speed recorded and the second is only for identification of car (and driver).
Because the cameras they use are deemed to be so reliable that they can calibrate them just once a year and stick the certificate on the safety camera partnership website, there are no road markings at most of their locations, as there is no need for the two pics to confirm the distance travelled.