摘要 |
<p>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. The method further comprises driving an Instrumented Probe Vehicle (IPV) (141) past the measurement point (132) , the IPV (141) having an onboard system for measuring speed, determining the location of the IPV, (141) determining a calibration time at which the determined location of the IPV (132) corresponds to the location of the measurement point (132), and measuring a calibration speed of the IPV (141) using the onboard system when the determined location of the IPV (141) corresponds to the location of the measurement point (132). The calibration time and speed are then sent to the TMS (101), and the recorded data pair corresponding to the calibration time is identified, enabling the speed of the IPV (141), as measured by the TMS (101), to be determined from said identified data pair; and compared with the calibration speed of the IPV (141), as measured by the onboard measuring system.</p> |