SIDRA INTERSECTION uses lane-based second-by-second arrival and departure flow patterns as a function of Signal Offsets to model signal platoons for internal approaches of Sites in coordinated signal systems and Common Control Groups. The model includes a unique platoon dispersion model.
Unlike traditional network models that use aggregate models of links or lane groups, the lane-based model for platoon movements between upstream and downstream Sites (on internal approaches) takes into account midblock lane changes that apply to second-by second platoon patterns. This is particularly important in evaluating closely-spaced (paired) intersections with high demand flows where vehicles have limited opportunities for lane changes between intersections. Midblock inflows and any interruptions due to queues of midblock opposed turns result in uniform flow patterns that disrupt good signal coordination plans. These requirements are important in modelling the forward movements of platoons for estimating performance measures (delay, back of queue, stop rate) as a function of signal offsets, geometric design and flow conditions.
SIDRA INTERSECTION network model also includes the use of extra bunching for signal platoons arriving at roundabouts and sign-controlled intersections for estimating the effect of upstream signals. Extra Bunching values are determined by the program automatically by default.