(cf STM Act, s 43A(4))
The
"average speed" of a vehicle between detection points is to be calculated in
accordance with the following formula (and expressed in kilometres per hour
rounded down to the next whole number)--
"DT" is the total shortest practicable distance (expressed in kilometres and rounded down to 2 decimal places) that could have been travelled by the vehicle on a road between the detection points.
"T" is the journey time (expressed in seconds) of the vehicle between the detection points.