ANALYSIS OF TRANSYT PLATOON-DISPERSION ALGORITHM

The development of an analytical solution to the recursive platoon-dispersion formula used in TRANSYT Models of traffic flow is presented. Flow rates in the predicted platoon measured at the kth interval of the jth simulated cycle are expressed in terms of demand and capacity rates at the source intersection in addition to signal-control and travel-time parameters. It was found that the TRANSYT recursive formula implicitly contains a cycle factor that results in an underestimation of the total flow rate simulated. An estimate of that error has been formulated, which can be applied as a constraint on the required simulation time in TRANSYT. The analytical solution also provided insight into the determination of critical intersection spacings below which signal coordination becomes feasible. (Author)