Evaluation of Operations and Safety in a Congested Freeway Merging Area with Auxiliary Through Lane
Highway and traffic engineers in the United States have recognized the importance of effective application of auxiliary lanes at high volume interchanges. Previous research has shown that congested merge areas with longer acceleration lanes appeared to increase the potential for collisions and operational problems due to the frequency of merging maneuvers over the total acceleration length, and implementing a no merging zone along the speed-change lane created safer and more efficient traffic operations. This study examines the I-40 and US 70 Bypass interchange near Garner, North Carolina, which consists of closely spaced ramps with an unbalanced number of lanes and poor application of auxiliary lanes, including an auxiliary through lane that begins and ends just beyond the subject interchange. The purpose of this study is to evaluate the balance in the number of lanes on closely spaced ramps and to evaluate if a congested merging area with poor application of auxiliary lanes is likely to worsen operations due to creating a greater potential for collisions. This study evaluates multiple low-cost alternative designs which should improve operational and safety problems identified in this congested merging area. The VISSIM Model is used to simulate the operations of the designs, and the FHWA Surrogate Safety Assessment Model is used to evaluate safety. This study amplifies the importance of appropriate auxiliary lanes and a need to implement a no-merging zone in a congested merging area.
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Supplemental Notes:
- This paper was sponsored by TRB committee AHB65 Operational Effects of Geometrics
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Corporate Authors:
500 Fifth Street, NW
Washington, DC United States 20001 -
Authors:
- Moon, Jae-Pil
- Reese, Michael P
- Dunlop, James H
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Conference:
- Transportation Research Board 91st Annual Meeting
- Location: Washington DC, United States
- Date: 2012-1-22 to 2012-1-26
- Date: 2012
Language
- English
Media Info
- Media Type: Digital/other
- Features: Figures; References; Tables;
- Pagination: 12p
- Monograph Title: TRB 91st Annual Meeting Compendium of Papers DVD
Subject/Index Terms
- TRT Terms: Auxiliary lanes; Highway design; Interchange ramps; Merging area; Merging traffic; Traffic congestion; Traffic lanes
- Identifier Terms: AASHTO Green Book
- Subject Areas: Design; Highways; Operations and Traffic Management; I22: Design of Pavements, Railways and Guideways; I73: Traffic Control;
Filing Info
- Accession Number: 01366426
- Record Type: Publication
- Report/Paper Numbers: 12-2825
- Files: TRIS, TRB
- Created Date: Mar 29 2012 7:14AM