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Title:

Access Design Safety Analysis for Managed Lanes Including Accessibility Level and Weaving Length

Accession Number:

01657961

Record Type:

Component

Abstract:

On expressways, Managed Lanes (MLs) have emerged as an effective dynamic traffic management strategy. MLs have been successfully implemented as an important facility in improving traffic mobility and in generating revenue for transportation agencies. Most of the previous studies of the MLs have only explored the safety impact of the whole MLs segments, without considering the safety effects of the access design. In this study, scenarios were built and tested with microsimulation to specify the safest accessibility level and to decide on the sufficient weaving length near access zones. The studied accessibility level varied from one to three accessibility levels along the network. The weaving length was defined as the distance per lane change to use the access zones from or to the ramps. The findings indicated that the conflict rate on MLs were 48% and 11% lower than that of General Purpose Lanes (GPLs) in the peak and the off-peak periods, respectively. A log-linear model was developed with estimation of odds multipliers for investigating the factors that affect the traffic conflicts in the studied segment. The result of the conflict frequency analysis suggested that one accessibility level was the safest option in the 9-miles network. The length of 1,000 feet per lane change was shown to be the safest weaving length near access zones. Additionally, a weaving length of 600 feet per lane change was not recommended. The findings of this study represent a further step towards improving access design of MLs.

Supplemental Notes:

This paper was sponsored by TRB committee AHB35 Standing Committee on Managed Lanes.

Report/Paper Numbers:

18-00860

Language:

English

Authors:

Saad, Moatz
Abdel-Aty, Mohamed
Lee, Jaeyoung
Wang, Ling

ORCID 0000-0001-7901-3995

Pagination:

6p

Publication Date:

2018

Conference:

Transportation Research Board 97th Annual Meeting

Location: Washington DC, United States
Date: 2018-1-7 to 2018-1-11
Sponsors: Transportation Research Board

Media Type:

Digital/other

Features:

Figures; References; Tables

Subject Areas:

Design; Highways; Operations and Traffic Management; Safety and Human Factors

Source Data:

Transportation Research Board Annual Meeting 2018 Paper #18-00860

Files:

TRIS, TRB, ATRI

Created Date:

Jan 8 2018 10:13AM