Signal timings at signalized intersections are frequently optimized by considering com monlyusedvehicle delay models.It is generally believed that reducing the average number of stops can also decrease the average veh...Signal timings at signalized intersections are frequently optimized by considering com monlyusedvehicle delay models.It is generally believed that reducing the average number of stops can also decrease the average vehicle delay.Therefore,the aim of this research is to address the question:“Can similar performance outcomes be achieved through the Minimization of Average Vehicle Delay(MAVD)and the Minimization of Average Number of Stops(MANS)?”The first phase of the study entails the creation of two distinct signal timing optimization models based on the Akcelik average vehicle delay and average number of stops models.Subsequently,scripts were developed in MATLAB to identify the optimal signal timings for both approaches utilizing the Differential Evolution Algorithm.In the third phase,30 traffic scenarios were generated,each varying in overall traffic vol umes at the intersection.Subsequently,the signal timings derived from the MAVD and MANSapproaches were applied independently to these scenarios,and performance indica tors(average vehicle delay and average number of stops)were compared.The results reveal that the utilization of MANS-based signal timings instead of MAVD may lead to an increase in average vehicle delays of up to 113.55%.Additionally,it is demonstrated that when MAVD-based signal timings are applied instead of MANS,the average number of stops can increase by up to 16.28%.Finally,it is concluded that as the overall traffic volume at the intersection increases,these growth rates tend to decrease.展开更多
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...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.展开更多
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 t...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%.展开更多
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.evaluat...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.展开更多
Signal timings at signalized intersections are frequently optimized by considering com monlyusedvehicle delay models.It is generally believed that reducing the average number of stops can also decrease the average veh...Signal timings at signalized intersections are frequently optimized by considering com monlyusedvehicle delay models.It is generally believed that reducing the average number of stops can also decrease the average vehicle delay.Therefore,the aim of this research is to address the question:“Can similar performance outcomes be achieved through the Minimization of Average Vehicle Delay(MAVD)and the Minimization of Average Number of Stops(MANS)?”The first phase of the study entails the creation of two distinct signal timing optimization models based on the Akcelik average vehicle delay and average number of stops models.Subsequently,scripts were developed in MATLAB to identify the optimal signal timings for both approaches utilizing the Differential Evolution Algorithm.In the third phase,30 traffic scenarios were generated,each varying in overall traffic vol umes at the intersection.Subsequently,the signal timings derived from the MAVD and MANSapproaches were applied independently to these scenarios,and performance indica tors(average vehicle delay and average number of stops)were compared.The results reveal that the utilization of MANS-based signal timings instead of MAVD may lead to an increase in average vehicle delays of up to 113.55%.Additionally,it is demonstrated that when MAVD-based signal timings are applied instead of MANS,the average number of stops can increase by up to 16.28%.Finally,it is concluded that as the overall traffic volume at the intersection increases,these growth rates tend to decrease.展开更多
This study evaluated the operational performance of Transit Signal Priority(TSP)using a microscopic simulation approach.The analysis was based on a 10-mile study corridor in South Florida.Two microscopic VISSIM simula...This study evaluated the operational performance of Transit Signal Priority(TSP)using a microscopic simulation approach.The analysis was based on a 10-mile study corridor in South Florida.Two microscopic VISSIM simulation models were developed:a Base model,calibrated and validated to represent field conditions,and a TSP model.With TSP,the study corridor experienced up to 8%reduction in travel times and up to 13.3% reduction in average vehicle delay time,for both buses and all other vehicles.To better quantify the mobility benefits of the TSP strategy,Mobility Enhancement Factors(MEFs)were developed,unlike previous studies.A MEF is a multiplicative factor to estimate the expected mobility level after implementing TSP at a specific site.A MEF<1 implies that the TSP yields mobility benefits.TSP’s impact on cross-streets were also estimated.The study results indicate TSP strategy has enhanced mobility for buses and all other vehicles.展开更多
文摘Signal timings at signalized intersections are frequently optimized by considering com monlyusedvehicle delay models.It is generally believed that reducing the average number of stops can also decrease the average vehicle delay.Therefore,the aim of this research is to address the question:“Can similar performance outcomes be achieved through the Minimization of Average Vehicle Delay(MAVD)and the Minimization of Average Number of Stops(MANS)?”The first phase of the study entails the creation of two distinct signal timing optimization models based on the Akcelik average vehicle delay and average number of stops models.Subsequently,scripts were developed in MATLAB to identify the optimal signal timings for both approaches utilizing the Differential Evolution Algorithm.In the third phase,30 traffic scenarios were generated,each varying in overall traffic vol umes at the intersection.Subsequently,the signal timings derived from the MAVD and MANSapproaches were applied independently to these scenarios,and performance indica tors(average vehicle delay and average number of stops)were compared.The results reveal that the utilization of MANS-based signal timings instead of MAVD may lead to an increase in average vehicle delays of up to 113.55%.Additionally,it is demonstrated that when MAVD-based signal timings are applied instead of MANS,the average number of stops can increase by up to 16.28%.Finally,it is concluded that as the overall traffic volume at the intersection increases,these growth rates tend to decrease.
基金supported by the National Natural Science Foundation of China under Grant Nos.71261016and 71401050the Program for New Century Excellent Talents in University under Grant No.NCET-12-1016+1 种基金the Natural Science Foundation of Inner Mongolia of China under Grant No.2014JQ03the Fundamental Research Funds for the Central Universities under Grant No.2013HGBZ0174
文摘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.
文摘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%.
基金supported by the National Nature Science Foundation of China(Grant No.51178343)。
文摘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.
文摘Signal timings at signalized intersections are frequently optimized by considering com monlyusedvehicle delay models.It is generally believed that reducing the average number of stops can also decrease the average vehicle delay.Therefore,the aim of this research is to address the question:“Can similar performance outcomes be achieved through the Minimization of Average Vehicle Delay(MAVD)and the Minimization of Average Number of Stops(MANS)?”The first phase of the study entails the creation of two distinct signal timing optimization models based on the Akcelik average vehicle delay and average number of stops models.Subsequently,scripts were developed in MATLAB to identify the optimal signal timings for both approaches utilizing the Differential Evolution Algorithm.In the third phase,30 traffic scenarios were generated,each varying in overall traffic vol umes at the intersection.Subsequently,the signal timings derived from the MAVD and MANSapproaches were applied independently to these scenarios,and performance indica tors(average vehicle delay and average number of stops)were compared.The results reveal that the utilization of MANS-based signal timings instead of MAVD may lead to an increase in average vehicle delays of up to 113.55%.Additionally,it is demonstrated that when MAVD-based signal timings are applied instead of MANS,the average number of stops can increase by up to 16.28%.Finally,it is concluded that as the overall traffic volume at the intersection increases,these growth rates tend to decrease.
基金sponsored by the Florida Department of Transportation(FDOT)and conducted as a cooperative effort by the Florida International University(FIU)and University of North Florida(UNF).
文摘This study evaluated the operational performance of Transit Signal Priority(TSP)using a microscopic simulation approach.The analysis was based on a 10-mile study corridor in South Florida.Two microscopic VISSIM simulation models were developed:a Base model,calibrated and validated to represent field conditions,and a TSP model.With TSP,the study corridor experienced up to 8%reduction in travel times and up to 13.3% reduction in average vehicle delay time,for both buses and all other vehicles.To better quantify the mobility benefits of the TSP strategy,Mobility Enhancement Factors(MEFs)were developed,unlike previous studies.A MEF is a multiplicative factor to estimate the expected mobility level after implementing TSP at a specific site.A MEF<1 implies that the TSP yields mobility benefits.TSP’s impact on cross-streets were also estimated.The study results indicate TSP strategy has enhanced mobility for buses and all other vehicles.
