Lane-based signal optimization with left turn prohibition in urban road networks

Left turns may generate efficiency problems, which can be solved by appropriately prohibiting left turns. The goal of this paper is to propose a method for purpose of minimizing total travel times in urban road networks by prohibiting left turns. With left turn prohibition, the signal timing plan is optimized with the lane-based method because the method can adequately handle both signal timing optimization and lane assignment. The total travel time is calculated with link flows and link travel time being estimated with signal settings. As illustrated by numerical examples, prohibiting left turns reduces the total travel time of car traffic in road networks. As the left turn prohibition results can handle the randomness in the network, these results provide potential implications for congestion management.

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Design of Signal Timing Plan for Urban Signalized Networks including Left Turn Prohibition

Journal of Advanced Transportation ◽

10.1155/2018/1645475 ◽

2018 ◽

Vol 2018 ◽

pp. 1-16 ◽

Cited By ~ 1

Author(s):

Qinrui Tang ◽

Bernhard Friedrich

Keyword(s):

Travel Time ◽

Treatment Options ◽

User Equilibrium ◽

Signal Timing ◽

Stochastic User Equilibrium ◽

Left Turn ◽

Traffic Demand ◽

Total Travel Time ◽

Left Turns ◽

Demand Patterns

Urban road networks may benefit from left turn prohibition at signalized intersections regarding capacity, for particular traffic demand patterns. The objective of this paper is to propose a method for minimizing the total travel time by prohibiting left turns at intersections. With the flows obtained from the stochastic user equilibrium model, we were able to derive the stage generation, stage sequence, cycle length, and the green durations using a stage-based method which can handle the case that stages are sharing movements. The final output is a list of the prohibited left turns in the network and a new signal timing plan for every intersection. The optimal list of prohibited left turns was found using a genetic algorithm, and a combination of several algorithms was employed for the signal timing plan. The results show that left turn prohibition may lead to travel time reduction. Therefore, when designing a signal timing plan, left turn prohibition should be considered on a par with other left turn treatment options.

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An analysis of mean link travel time in urban road networks and its applications

SICE Annual Conference 2007 ◽

10.1109/sice.2007.4421209 ◽

2007 ◽

Author(s):

Hikaru Shimizu ◽

Masa-aki Kobayashi ◽

Haruko Fujii ◽

Shigekazu Katagiri

Keyword(s):

Travel Time ◽

Road Networks ◽

Urban Road ◽

Link Travel Time

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Operational Effects of the Consolidated Intersection Design on Urban and Suburban Arterials

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198118792754 ◽

2018 ◽

Vol 2672 (17) ◽

pp. 96-107

Author(s):

Daniel J. Cook

Keyword(s):

Travel Time ◽

Signalized Intersections ◽

Signal Timing ◽

Left Turn ◽

Vehicle Delay ◽

Cycle Lengths ◽

Expected Benefits ◽

Traffic Signal Timing ◽

Critical Phases ◽

Pedestrian Crossing

Along urban and suburban arterials, closely-spaced signalized intersections are commonly used to provide access to adjacent commercial developments. Often, these signalized intersections are designed to provide full access to developments on both sides of the arterial and permit through, left-turn, and right-turn movements from every intersection approach. Traffic signal timing is optimized to reduce vehicle delay or provide progression to vehicles on the arterial, or both. However, meeting both of these criteria can be cumbersome, if not impossible, under high-demand situations. This research proposes a new design that consolidates common movements at three consecutive signalized intersections into strategic fixed locations along the arterial. The consolidation of common movements allows the intersections to cycle between only two critical phases, which, in turn, promotes shorter cycle lengths, lower delay, and better progression. This research tested the consolidated intersection concept by modeling a real-world site in microsimulation software and obtaining values for delay and travel time for multiple vehicle paths along the corridor and adjacent commercial developments in both existing and proposed conditions. With the exception of unsignalized right turns at the periphery of the study area, all non-displaced routes showed a reduction in travel time and delay. Additional research is needed to understand how additional travel through the commercial developments adjacent to the arterial may effect travel time and delay. Other expected benefits of the proposed design include a major reduction in conflict points, shorter pedestrian crossing and wait times, and the opportunity to provide pedestrian refuge areas in the median.

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