Influence of midblock U-turn facility on traffic flow reduction and its effect on kinematic wave propagation

Midblock median opening facilities are constructed on multilane highways in Malaysia solely for the purpose of facilitating U-turn movements along federal road segments. In Malaysia, a persistence problem of traffic conflicts and congestion at multi-lane highway intersections forced the federal auth...

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Main Author: Abd. Rahman, Raha
Format: Thesis
Language:English
Published: 2014
Subjects:
Online Access:http://eprints.utm.my/id/eprint/78415/1/RahaAbdRahmanPFKA2014.pdf
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spelling my-utm-ep.784152018-08-26T04:56:29Z Influence of midblock U-turn facility on traffic flow reduction and its effect on kinematic wave propagation 2014-11 Abd. Rahman, Raha TA Engineering (General). Civil engineering (General) Midblock median opening facilities are constructed on multilane highways in Malaysia solely for the purpose of facilitating U-turn movements along federal road segments. In Malaysia, a persistence problem of traffic conflicts and congestion at multi-lane highway intersections forced the federal authorities to invest in midblock median opening facilities as traffic conflict reduction mechanism. Although the authorities have succeeded in reducing traffic conflicts at intersections, the realisation of maximum traffic flow at the midblock zone is in doubt. The aim of the study is to determine influence of midblock U-turn facility on traffic flow reduction and its effect on kinematic wave propagation. The objectives are to determine traffic volume, speeds as well as vehicle types at the midblock and free-flow zones for both directional flows. As well as examine the effect of traffic flow reduction on kinematic wave propagation. It was assumed that traffic density was a resultant of speed and traffic flow hence not directly affected by midblock zone. It implies that traffic flow reduction was fully the result of speed changes. Where traffic flow reduction has occurred, the ensuing kinematic wave propagation would be investigated in order to determine whether it is a rarefaction wave or traffic shockwave. Vehicle types, traffic volumes and vehicles speeds were collected using automatic traffic counters at each directional flow of the four surveyed sites for six months. The survey data were collated and analysed. Passenger car equivalent values were modified and used to convert traffic volume to flow. Results show that midblock facility would cause about 4 per cent reduction in traffic flow at the diverging section and 10 per cent reduction in traffic at the merging section. The findings give traffic capacity values under different scenarios and can be incorporated into a wider strategy for dynamic traffic management. Findings from kinematic wave propagations confirm that midblock facility would cause traffic shock wave at the merging not the diverging section. Estimated traffic flow reduction from the study can be used as evidence to highlight the need to redesign midblock facility in Malaysia. One possible solution among others is to incorporate appropriate acceleration lane at the merging section thereby minimising the potential for vehicle collision. The study concluded that midblock facility will cause traffic significant flow reduction. 2014-11 Thesis http://eprints.utm.my/id/eprint/78415/ http://eprints.utm.my/id/eprint/78415/1/RahaAbdRahmanPFKA2014.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:98560 phd doctoral Universiti Teknologi Malaysia, Faculty of Civil Engineering Faculty of Civil Engineering
institution Universiti Teknologi Malaysia
collection UTM Institutional Repository
language English
topic TA Engineering (General)
Civil engineering (General)
spellingShingle TA Engineering (General)
Civil engineering (General)
Abd. Rahman, Raha
Influence of midblock U-turn facility on traffic flow reduction and its effect on kinematic wave propagation
description Midblock median opening facilities are constructed on multilane highways in Malaysia solely for the purpose of facilitating U-turn movements along federal road segments. In Malaysia, a persistence problem of traffic conflicts and congestion at multi-lane highway intersections forced the federal authorities to invest in midblock median opening facilities as traffic conflict reduction mechanism. Although the authorities have succeeded in reducing traffic conflicts at intersections, the realisation of maximum traffic flow at the midblock zone is in doubt. The aim of the study is to determine influence of midblock U-turn facility on traffic flow reduction and its effect on kinematic wave propagation. The objectives are to determine traffic volume, speeds as well as vehicle types at the midblock and free-flow zones for both directional flows. As well as examine the effect of traffic flow reduction on kinematic wave propagation. It was assumed that traffic density was a resultant of speed and traffic flow hence not directly affected by midblock zone. It implies that traffic flow reduction was fully the result of speed changes. Where traffic flow reduction has occurred, the ensuing kinematic wave propagation would be investigated in order to determine whether it is a rarefaction wave or traffic shockwave. Vehicle types, traffic volumes and vehicles speeds were collected using automatic traffic counters at each directional flow of the four surveyed sites for six months. The survey data were collated and analysed. Passenger car equivalent values were modified and used to convert traffic volume to flow. Results show that midblock facility would cause about 4 per cent reduction in traffic flow at the diverging section and 10 per cent reduction in traffic at the merging section. The findings give traffic capacity values under different scenarios and can be incorporated into a wider strategy for dynamic traffic management. Findings from kinematic wave propagations confirm that midblock facility would cause traffic shock wave at the merging not the diverging section. Estimated traffic flow reduction from the study can be used as evidence to highlight the need to redesign midblock facility in Malaysia. One possible solution among others is to incorporate appropriate acceleration lane at the merging section thereby minimising the potential for vehicle collision. The study concluded that midblock facility will cause traffic significant flow reduction.
format Thesis
qualification_name Doctor of Philosophy (PhD.)
qualification_level Doctorate
author Abd. Rahman, Raha
author_facet Abd. Rahman, Raha
author_sort Abd. Rahman, Raha
title Influence of midblock U-turn facility on traffic flow reduction and its effect on kinematic wave propagation
title_short Influence of midblock U-turn facility on traffic flow reduction and its effect on kinematic wave propagation
title_full Influence of midblock U-turn facility on traffic flow reduction and its effect on kinematic wave propagation
title_fullStr Influence of midblock U-turn facility on traffic flow reduction and its effect on kinematic wave propagation
title_full_unstemmed Influence of midblock U-turn facility on traffic flow reduction and its effect on kinematic wave propagation
title_sort influence of midblock u-turn facility on traffic flow reduction and its effect on kinematic wave propagation
granting_institution Universiti Teknologi Malaysia, Faculty of Civil Engineering
granting_department Faculty of Civil Engineering
publishDate 2014
url http://eprints.utm.my/id/eprint/78415/1/RahaAbdRahmanPFKA2014.pdf
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