SCOOT Compared

The real time traffic network optimization program SCOOT is well known worldwide as an optimization program for controlled networks in urban area's. Apart from applications in the United Kingdom, the use of SCOOT has been reported from Beijing (China), Toronto (Canada), Madrid (Spain) and from Minneapolis (United States). This paper describes the way in which SCOOT was implemented, calibrated, tested and assessed against the existing control system in the city of Nijmegen in The Netherlands. It was explicitly decided not to develop a new real-time control system, but to consider the possibilities and applicability of an existing system. After a call for tender, the implementation started in July 1991. Completion was foreseen by the end of 1992 but turned out to be somewhat delayed, due to several reasons which will be explained. The calibration was completed in September 1993. In the assessment phase, attention was paid to the differences with respect to the measurement of journey times through the network, not only for passenger cars, but also for public transport, pedestrians and bicycles. Other important aspects were the number of stops and the queue length. These aspects were measured on several locations in the network, including those locations where the gating mechanism was active. The data-processing and -analysis finished in January 1995. The analysis showed that the starting-point of the assessment (a SCOOT system that is validated correctly) was not entirely correct which put a finger on a weak spot. In general the differences are varying. SCOOT gives a better performance in the morning peak, but a worse performance in the evening peak. On the whole there is no difference between the SCOOT system and the old system and that accounts for all modes of transport.