Evaluation and Effectiveness of Reallocating Traffic Signal Timing at Corridors with High Freight Volume

The COVID-19 pandemic drastically altered traffic patterns across the globe.With more people staying at home and relying on delivery services,there was a reduction in passenger car traffic but an increase in freight traffic.This study investigates the changes in traffic volume and mode splits during the COVID-19 pandemic at the intersection of Broening Highway and Holabird Avenues and investigates traffic signal reallocation strategies that account for the changes in traffic.This study considers morning peak traffic volumes before and during COVID.A methodology was developed to evaluate and measure freight volumes and emissions.From the literature,the cost per kilogram of CO,VOC,and NOx was$5.85,$3,37,and$12.53,respectively.The intersection operated at a level of service(LOS)of C both pre-COVID and during COVID.Traffic volume decreased by 24.3%during COVID at the study location;car volumes declined by 50%,and truck volumes increased by 130%.The total rate of emissions decreased by 22.6%.

Delays for Both Pedestrians Classified and Vehicles at a Signalized Crosswalk

Delays of both pedestrians,who are classified according to whether complying with traffic law,and vehicles at a signalized crosswalk are analyzed in this paper.The truncated Adams' model is applied to generate the probability and mean of delay of pedestrians non-complying with traffic law.Using the section-based traffic queuing-theory and the stochastic decomposition property of M/G/1vacation system with exhaustive service,the mean delay of vehicles is formulated.A multi-objective optimization model simultaneously minimizing the delays of pedestrians and vehicles during a signal period is proposed.The effects,which several model parameters have on the delays and the optimal solution of the model,are illustrated by numerical examples.

A flexible model-free tram signal priority method with a large coordination scope in China

Tram systems with the advantages of reliable operation,comfort,low emissions and moderate capacity have been quite popular in recent years in China.However,there are still problems with tram signal control(e.g.evaluation model,signal control strategies).In-depth analysis on existing operational issues of trams,calculation of two evaluation indexes,as well as a flexible model-free tram signal priority method were developed to deal with tram problems.Empirical research in Songjiang District,Shanghai shows that:(1)The function of the green extension strategy is limited with c.a.10%tram priority improvement,while the optimal one can reach to 85%higher on average.(2)A scheme with a benefit for trams and with no negative impact,and even benefits,for general traffic can be realized.(3)The optimal solution is beneficial for intersections with a maximum c.a.70%amelioration with delay decreasing from 132.7 s/vehicle to 40.89 s/vehicle,or from 104.77 s/capita to 22.31 s/capita.This paper has great significance for the signal optimization and safety of tram systems,even the development of a comprehensive transportation system for a city.