Abstract
The stated objective of the investigation was to develop, calibrate and, as far as possible, validate a behavioural model of drivers' responses to the changing of traffic signals at the end of green, the model being so formulated that it can be used to estimate the effect on drivers' responses of a range of possible modifications to the way in which the signals change from green for one set of streams to green for other conflicting streams, allowing for the possibility of risk compensation. As reported here, many important behavioural, physical and mathematical elements of such a model have been specified and a good deal of calibration has been undertaken.