Abstract: An apparatus and method are provided for monitoring, remotely, information relating to the motion of at least one moving object. The apparatus comprises: means for illuminating a retro-reflective data carrier mounted on each moving object, in particular when the moving object is located at a predetermined monitoring position; means for detecting, in optical signals returned by the retro-reflective data carrier, data representing a timing trigger and data representing an identifier for the at least one moving object; timer means responsive to a timing trigger detected at the predetermined monitoring position to trigger a timer associated with a detected identifier; and an output to provide timing information associated with the detected identifier, and hence relating to the at least one moving object at the predetermined monitoring position. The timing information may be used to derive relative ordering, relative timing or speeds of moving objects, for example.