Having read the discussion fairly recently about checking your speed using mile posts on the motorway I thought I'd have a go myself. On the M5 between Bristol and Gloucester I cannot find anything that is a mile apart. Am I correct in assuming that you use the little white posts with a blue band around the top that tell you where the nearest phone is? These have numbers on them which do count up/down eg. 57/9,
57/8....57/0, 56/9. Trouble is at an indicated 70 I pass 18 of these in a minute. However if they are 0.1Km posts then this would give an approximate speed of 66mph which, given the errors in the experiment, is about spot on.- posted
19 years ago