Originally Posted by MikeCC
I always thought there was a 10% margin of error for speedos?
In the 30 limits around here they set the temporary units up in 30 zones for around 36-37mph (about the only useful bit of information the local paper has ever published!)
No allowance is made these days for speedo error.
The Association of Chief Police Officers (ACPO) did offer guidance on GATSO type prosecution which allowed for 10% plus 2mph - thus 35 in a 30, 46 in a 40 etc. This was not acknowledging machine error, but allowed the police reasonable discretion when setting speed traps, and avoided the undue prosecution (and flooding of the system) that catching 97% of drivers would produce..
With Automatic Number Plate Recognition (ANPR), and type approval of speed detection devices, no allowance for speed above the limit need be made and the detection and prosecution are automated. Wet film type GATSOs still may be set above the posted limit, may contain dummy flash units and still run out of film.
In Germany they cut them down with pipe cutters...much better than a Soweto necklace if you ask me!