Evaluation of Effectiveness of Coordinated Signal Control on Reducing Vehicle Emissions during Peak Hours vs. Non-peak Hours

摘要

Traffic signal coordination is not only an effective traffic operational strategy tosmooth the traffic in urban areas, but also considered a potentially effective means toreduce vehicle emissions. Nevertheless, when the traffic flow speed decreases, theeffectiveness of using the traffic signal coordination to reduce emissions may besubstantially weakened. This paper is intended to evaluate the effectiveness of thesignal coordination on reducing vehicle emissions during peak- vs. non-peak-hours,two different speed scenarios. The operating mode binning approach is used as astatistical technique to calculate emission rates, and the difference of emissions isadopted as the measure of effectiveness in the study. Data used in the study includeGPS data and emission data collected from the real-world tests. It is found from thestudy that the coordinated signal control can reduce vehicle emissions in the order of,from the top to the bottom, NO_x, CO_2, HC and CO. However, its effectiveness will beimpaired during peak hours when the speed is decreased. Meanwhile, the test showsthat the effectiveness will be affected by the drivers' behaviors. Either the low averagespeed or the intentionally slow driving will weaken the effectiveness of thecoordinated control on reducing vehicle emissions.