Abstract: The present invention relates to an indicium identifying system. The system comprises at least one image sensor (100) for imaging an indicium; an illuminator (102) for illuminating said indicium; and a processor (104) adapted to receive images of the indicium from the at least one image sensor (100) and process said image to determine said indicium, wherein the illuminator (102) is adapted to emit a series of light pulses of varying intensity. This invention extends to a corresponding method.

Abstract: A method of monitoring traffic flow comprises reading registration plates of the vehicles of a multiplicity of series of vehicles passing respective locations on a road network, if necessary selecting samples of readings from the readings relating to the vehicles of the series, and determining whether readings of the samples are deemed to contain matching readings. The samples are used as probes or targets to measure average journey times which are compared with reference journey times. The selecting of the samples at the respective reading locations is performed according to an algorithm common to all of the locations.