Signal Coordination and Adaptive Traffic Control under Heterogeneous Traffic Condition: Study of Keshar Mahal and Durbar Marg Intersections

Two intersections namely Keshar Mahal and Durbar Marg lie close to each other with a linkage distance of only 210m between them. The currently functioning traffic management system is unable to clear the intersections quickly causing very long queue lengths. The spillback from one intersection is extending beyond the upstream intersection causing failure of that intersection. Vehicles encounter a cumulative delay at both the intersections with intermittent stops. This study aims to develop urban intersection models for signal coordination and adaptive traffic control under heterogenous traffic conditions using an advanced lane-based micro-analytical tools the SIDRA INTERSECTION 8.0 in order to improve operational performance. The operational performance of the existing study intersections was evaluated from the calibrated and validated SIDRA model. Simulations for different alternatives of phase configuration and cycle timing were run under isolated and coordinated conditions for pretimed and actuated signalization. Signal coordination under pretimed signalization and optimal network signal cycle was found to be the best signalization option. In the base year, it was found that there would be a total travel time saving of 245 veh-h/h (33.4%) when signals were coordinated under pretimed signalization. The total control delay in the network would decrease by 229 veh-h/h (48.8%). In the forecasted year (10 years later), it was found that there would be a total travel time saving of 24.9 veh-h/h (1.1%). The total control delay in the network would decrease by 37 veh-h/h (2%). The analysis showed that signal coordination under pretimed signalization and optimal network signal cycle cleared the intersections quickly minimizing queue length without causing failure of upstream intersection and intermittent stops. Signal coordination would be a better option to improve operational performance which does not require any geometric improvement.