Emission factor calibration and signal timing optimisation for isolated intersections

Abstract

Signal control strategy has a huge effect not only on intersection operations but also on traffic emissions. The basic assumptions are first proposed. Using the second-by-second data of vehicular velocity and acceleration, the mathematical expressions are then presented to calibrate the emission factors during green/red on the basis of vehicle-specific power. Given some necessary constraints, a single-objective optimisation model and a bi-objective optimisation model are formulated with the concern of traffic emissions. Considering three levels of traffic demands and two methods of signal timing, the numerical examples are carried out by utilising the VISSIM and MATLAB software packages. The findings indicate that the emission factors during green are explicitly greater than those during red and they are all stable for each pollutant and for each lane group; a scientific signal control system can simultaneously reduce vehicle delay and traffic emissions for isolated intersections.