Urban signalized intersections usually are among the worst spots in a transportation network to incur congestion and pollution, where vehicles are obliged to stop, accelerate or decelerate, thereby generating delay and emissions. This study explores both vehicle delay and emissions for signalized intersections by utilizing the cell transmission model (CTM), which is a kind of mesoscopic traffic simulation model that offers the advantage of simplicity and computation speed compared with microscopic models, and accuracy compared with macroscopic models. To validate the effectiveness of CTM in modeling delay and emissions, comparisons with a microscopic car-following model and macroscopic models, are carried out on a real road network in Hong Kong. The numerical results are encouraging, de...[ Read more ]

Urban signalized intersections usually are among the worst spots in a transportation network to incur congestion and pollution, where vehicles are obliged to stop, accelerate or decelerate, thereby generating delay and emissions. This study explores both vehicle delay and emissions for signalized intersections by utilizing the cell transmission model (CTM), which is a kind of mesoscopic traffic simulation model that offers the advantage of simplicity and computation speed compared with microscopic models, and accuracy compared with macroscopic models. To validate the effectiveness of CTM in modeling delay and emissions, comparisons with a microscopic car-following model and macroscopic models, are carried out on a real road network in Hong Kong. The numerical results are encouraging, demonstrating the reliability of CTM for evaluating delay and emission in signalized intersections. Compared with transportation demand management (TDM) measures for congestion and emission alleviation, traffic control management (TCM) measures for traffic flow improvement are much more cost-effective and one of the most common practices. To investigate the performance of different signal control strategies, the correlation analysis of delay and emission optimization is carried on using shockwave model in the case of fixed demand. It is found that not much tradeoff exists between delay and emissions optimization for an isolated signalized intersection. For generalization, CTM is used for time-dependent traffic dynamics with an empirical study on coordinated signalized intersections. The results show that the signal timing plans which minimize delay also to a large degree minimize emissions.