Impact of Using Indirect Left-turns on Signalized Intersections

A Master of Science thesis in Civil Engineering by Mahmoud Ahmed Taha entitled, "Impact of Using Indirect Left-turns on Signalized Intersections," submitted in June 2015. Thesis advisor is Dr. Akmal Abdelfatah. Soft and hard copy available.

محفوظ في:
التفاصيل البيبلوغرافية
المؤلف الرئيسي: Taha, Mahmoud Ahmed (author)
التنسيق: doctoralThesis
منشور في: 2015
الموضوعات:
الوصول للمادة أونلاين:http://hdl.handle.net/11073/7838
الوسوم: إضافة وسم
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_version_ 1864513434056392704
author Taha, Mahmoud Ahmed
author_facet Taha, Mahmoud Ahmed
author_role author
dc.contributor.none.fl_str_mv Abdelfatah, Akmal
dc.creator.none.fl_str_mv Taha, Mahmoud Ahmed
dc.date.none.fl_str_mv 2015-06-29T10:15:16Z
2015-06-29T10:15:16Z
2015-06
dc.format.none.fl_str_mv application/pdf
dc.identifier.none.fl_str_mv 35.232-2015.20
http://hdl.handle.net/11073/7838
dc.language.none.fl_str_mv en_US
dc.subject.none.fl_str_mv Traffic Signal optimization
Indirect left-turns
Microscopic simulation
Direct left-turn (DLT)
DLT
Right-turn followed by a U-turn (RTUT)
RTUT
U-turn followed by a right-turn (UTRT)
UTRT
Vehicle Kilometers Travelled (VKT)
VKT
Traffic engineering
Traffic flow
Roads
Interchanges and intersections
Traffic signs and signals
dc.title.none.fl_str_mv Impact of Using Indirect Left-turns on Signalized Intersections
dc.type.none.fl_str_mv info:eu-repo/semantics/publishedVersion
info:eu-repo/semantics/doctoralThesis
description A Master of Science thesis in Civil Engineering by Mahmoud Ahmed Taha entitled, "Impact of Using Indirect Left-turns on Signalized Intersections," submitted in June 2015. Thesis advisor is Dr. Akmal Abdelfatah. Soft and hard copy available.
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network_acronym_str aus
network_name_str aus
oai_identifier_str oai:repository.aus.edu:11073/7838
publishDate 2015
repository.mail.fl_str_mv
repository.name.fl_str_mv
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spelling Impact of Using Indirect Left-turns on Signalized IntersectionsTaha, Mahmoud AhmedTraffic Signal optimizationIndirect left-turnsMicroscopic simulationDirect left-turn (DLT)DLTRight-turn followed by a U-turn (RTUT)RTUTU-turn followed by a right-turn (UTRT)UTRTVehicle Kilometers Travelled (VKT)VKTTraffic engineeringTraffic flowRoadsInterchanges and intersectionsTraffic signs and signalsA Master of Science thesis in Civil Engineering by Mahmoud Ahmed Taha entitled, "Impact of Using Indirect Left-turns on Signalized Intersections," submitted in June 2015. Thesis advisor is Dr. Akmal Abdelfatah. Soft and hard copy available.Most developing areas are suffering from traffic congestion problems. The majority of traffic delays in urban areas occur at traffic signals. Over the past few decades, several transportation agencies have been applying geometric changes, through adding more lanes, to signalized intersections in an effort to reduce delays. Because of the limited availability of right-of-way, many transportation agencies have started using unconventional traffic control systems for intersections to improve signal efficiency and reduce overall delays. Common unconventional left-turn control types such as the right-turn followed by a U-turn (RTUT) and a U-turn followed by a right-turn (UTRT) basically eliminate direct left-turn (DLT) movements at the intersection by rerouting left-turning vehicles away from the main junction. Following any of these alternatives reduces the number of phases and the average delay per vehicle at the main junction. However, it adds some additional travel time for left-turning vehicles and some delays at the U-turn locations. This thesis presents a parametric study to evaluate the impact of replacing direct left-turns with U-turns (either RTUT or UTRT). The main goal of this study is to determine the traffic operational performance of each alternative under different traffic conditions. Traffic signal evaluation (Synchro) and simulation (Vissim) tools were utilized in this study to determine the optimized signal timings and evaluate intersection performance for each left-turn control type, respectively. Many parameters were considered, such as the total traffic volume on the intersection, the percentage of vehicles on each approach, the turning percentage for each movement, and the U-turn locations. It was concluded that unconventional left-turn control types have less delay and travel time compared to the DLT, when the U-turn locations are 200 meters away from the main intersection. Also, the right-turn followed by a U-turn showed superior performance over the other left-turn control types, when the U-turn locations are 100 meters away from the main intersection. Furthermore, it is not recommended to have the U-turns at a distance less than 100 meters when using unconventional left-turn control types because of the queue spillback effect. Finally, both conventional and unconventional control types have comparable vehicle kilometers travelled (VKT).College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE)Abdelfatah, Akmal2015-06-29T10:15:16Z2015-06-29T10:15:16Z2015-06info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisapplication/pdf35.232-2015.20http://hdl.handle.net/11073/7838en_USoai:repository.aus.edu:11073/78382025-06-26T12:29:03Z
spellingShingle Impact of Using Indirect Left-turns on Signalized Intersections
Taha, Mahmoud Ahmed
Traffic Signal optimization
Indirect left-turns
Microscopic simulation
Direct left-turn (DLT)
DLT
Right-turn followed by a U-turn (RTUT)
RTUT
U-turn followed by a right-turn (UTRT)
UTRT
Vehicle Kilometers Travelled (VKT)
VKT
Traffic engineering
Traffic flow
Roads
Interchanges and intersections
Traffic signs and signals
status_str publishedVersion
title Impact of Using Indirect Left-turns on Signalized Intersections
title_full Impact of Using Indirect Left-turns on Signalized Intersections
title_fullStr Impact of Using Indirect Left-turns on Signalized Intersections
title_full_unstemmed Impact of Using Indirect Left-turns on Signalized Intersections
title_short Impact of Using Indirect Left-turns on Signalized Intersections
title_sort Impact of Using Indirect Left-turns on Signalized Intersections
topic Traffic Signal optimization
Indirect left-turns
Microscopic simulation
Direct left-turn (DLT)
DLT
Right-turn followed by a U-turn (RTUT)
RTUT
U-turn followed by a right-turn (UTRT)
UTRT
Vehicle Kilometers Travelled (VKT)
VKT
Traffic engineering
Traffic flow
Roads
Interchanges and intersections
Traffic signs and signals
url http://hdl.handle.net/11073/7838