Vehicle delay is an important measure to evaluate the signal timings of signalized intersections.When optimization the signal control parameters, delays of vehicles from all approach directions of an intersection shou...Vehicle delay is an important measure to evaluate the signal timings of signalized intersections.When optimization the signal control parameters, delays of vehicles from all approach directions of an intersection should be considered. Based on the analysis of the vehicle delay on an approach of intersection, directed against the typical condition of a congested intersection-over-saturated condition, the paper has analyzed and inferred the intersection delay dynamic formulation, and has established the relation between intersection delay,the signal timings, vehicle arrival rate and the queue lengths, and that provides useful information for understanding vehicle delay of signalized intersection and for establishing performance index function of signal timing optimization.展开更多
Delay in signalized intersections may constitute a significant part of bus journey times in urban environment. Providing priority for buses at traffic signals can be an effective measure to reduce this delay. Bus prio...Delay in signalized intersections may constitute a significant part of bus journey times in urban environment. Providing priority for buses at traffic signals can be an effective measure to reduce this delay. Bus priority in Swedish urban traffic signal systems are normally coordinated with fixed time plan selection. Within this framework local traffic actuated signal timing adjustments are applied based on detector inputs aimed to reduce the number of vehicles in the dilemma zone. Active bus priority is also achieved with the aim to display green signal at the arrival of the bus to the stop line. Due to lack of knowledge of traffic performance impacts of these techniques a major research study was undertaken funded by the Swedish Road Administration. The aim was to evaluate the following control strategies using Stockholm as case study： （1） Fixed time coordination （FTC）; （2） Fixed time coordination with local signal timing adjustment （FTC-LTA）; （3） FTC-LTA with active bus priority （PRIBUSS）; （4） Self-optimizing control （SPOT） with active bus priority. The methodologies for the study included field data collection using mobile and stationary techniques, offiine signal timing calculations with TRANSYT, microscopic simulation modeling using the HUTSIM model. The study obtained the following results： （1） Local traffic adjustment with the manual FTC reduced total delay by 1%. （2） Signal timings determined using TRANSYT reduced the average intersection delay by 9% compared to manual signal settings. （3） Local traffic adjustment reduced total delay by a further 5%. （4） Bus travel time was reduced by 11% using PRIBUSS, and 28% using SPOT. （5） Travel time for all vehicles did not increase using PRIBUSS, and was reduced by 6.5% with SPOT. Results of comparing PRIBUSS and SPOT to FTC-LTA were shown to be statistically significant.展开更多
基金Sponsored by the Mulfidiscipline Scientific Research Foundation of Harbin Institute of Technology( Grant No. HIT. MD. 2002.28)
文摘Vehicle delay is an important measure to evaluate the signal timings of signalized intersections.When optimization the signal control parameters, delays of vehicles from all approach directions of an intersection should be considered. Based on the analysis of the vehicle delay on an approach of intersection, directed against the typical condition of a congested intersection-over-saturated condition, the paper has analyzed and inferred the intersection delay dynamic formulation, and has established the relation between intersection delay,the signal timings, vehicle arrival rate and the queue lengths, and that provides useful information for understanding vehicle delay of signalized intersection and for establishing performance index function of signal timing optimization.
文摘Delay in signalized intersections may constitute a significant part of bus journey times in urban environment. Providing priority for buses at traffic signals can be an effective measure to reduce this delay. Bus priority in Swedish urban traffic signal systems are normally coordinated with fixed time plan selection. Within this framework local traffic actuated signal timing adjustments are applied based on detector inputs aimed to reduce the number of vehicles in the dilemma zone. Active bus priority is also achieved with the aim to display green signal at the arrival of the bus to the stop line. Due to lack of knowledge of traffic performance impacts of these techniques a major research study was undertaken funded by the Swedish Road Administration. The aim was to evaluate the following control strategies using Stockholm as case study： （1） Fixed time coordination （FTC）; （2） Fixed time coordination with local signal timing adjustment （FTC-LTA）; （3） FTC-LTA with active bus priority （PRIBUSS）; （4） Self-optimizing control （SPOT） with active bus priority. The methodologies for the study included field data collection using mobile and stationary techniques, offiine signal timing calculations with TRANSYT, microscopic simulation modeling using the HUTSIM model. The study obtained the following results： （1） Local traffic adjustment with the manual FTC reduced total delay by 1%. （2） Signal timings determined using TRANSYT reduced the average intersection delay by 9% compared to manual signal settings. （3） Local traffic adjustment reduced total delay by a further 5%. （4） Bus travel time was reduced by 11% using PRIBUSS, and 28% using SPOT. （5） Travel time for all vehicles did not increase using PRIBUSS, and was reduced by 6.5% with SPOT. Results of comparing PRIBUSS and SPOT to FTC-LTA were shown to be statistically significant.
