The effectiveness of SCATS Master Isolated (SMI) control for non-coordinated signalised intersections was evaluated using vehicle-by-vehicle simulation including an evaluation of the effects of detector failure, as well as field surveys. Various SCATS-like adaptive control algorithms were developed and tested through extensive simulation tests with a wide range of demand flow patterns and a large number of control parameter combinations. Traditional vehicle-actuated and fixed-time control were also evaluated. The results for Algorithm 9, which was closest to the SMI method, and the traditional vehicle-actuated control method are presented in this paper. A new survey method was developed, trialled and used for the surveys. The overall conclusion is that SMI control gives better intersection performance than traditional VA control. The SMI green splits based on the equal degree of saturation principle tend to favour major movements. Evaluation of various detector failure cases indicated substantial benefits from the SCATS Master Isolated control method in terms of all performance measures considered. Longer cycle times, higher degrees of saturation and substantially longer delays (including minor movements) and queue lengths were observed with the traditional VA control. (A)
Abstract