Delay Model Revisited Considering Channelized Section Spillover

摘要

Delay is a key parameter in traffic signal optimization, and traditionally is calculated for directional movements. When channelized section spillover (CSS) occurs, turning flows interact with each other. If there are multiple potential spillover queues, the first spillover event will cut the flow off, and change the growth of other queues, further altering the evolution of the whole approach. Under such circumstances, the directional delays interrelate. A new delay model which can consider the CSS is necessary. This research identifies three components of extra delay caused by CSS: 1) delay due to spillover; 2) delay caused by the first-in-first-out (FIFO) principle; and 3) delay due to the saturation flow degradation. A numerical simulation is implemented to quantify the three components. It is found that delay when CSS occurs is a function of at least three groups of variables: 1) signal settings; 2) all directional flows; and 3) intersection approach attributes.