Abstract: A verification apparatus for testing a loop detection system or loop sensor comprises one or more verification loops (222, 203, 223, 204) for placing adjacent the loop sensor (401, 402) and impedance varying means (303, 304) for varying the impedance of the or each verification loop. The change in impedance may be caused to move along the apparatus so as to simulate the passage of a vehicle past the loop sensor.

Abstract: A roadside traffic monitoring system comprises a primary sensor for measuring a parameter of vehicles passing a measurement point and a secondary sensor for measuring the same parameter of vehicles as they pass the measurement point. The secondary sensor is able to measure the parameter to a higher level of accuracy than the primary sensor but only under certain predetermined conditions. The system further comprises a conditions sensor for determining when these predetermined conditions are met, enabling the secondary sensor to be used to calibrate the primary sensor.

Abstract: A method of assessing the accuracy of a roadside traffic monitoring station (TMS) (01) arranged to measure the speed and/or other parameters of vehicles passing a predetermined measurement point (132) adjacent the TMS (101) is disclosed. The method comprises measuring the speed of each vehicle passing the measurement point (132) using the TMS (101), measuring the moment in time that each vehicle passes the measurement point (132) using the TMS (101), and recording the measured speeds and times as data pairs.