01660162

Component

An Active Traffic Management (ATM) system was activated on I-66 in Northern Virginia between US 29 in Centreville and the Capital Beltway (I-495) in September 2015. The ATM system included advisory variable speed limits (AVSLs), lane use control signals (LUCS), and dynamic hard shoulder running (HSR). The goal of this system was to improve safety and operations on I-66 without physically expanding the existing roadway. This paper quantifies the operational and safety effects of the ATM system on I-66 using 1 year of crash data following system activation and 1.5 years of operational data. The operational analysis showed that off peak hours experienced significant travel time improvement after the ATM system was activated, but peak periods in the peak direction of travel generally did not see improvement. Further analysis revealed that most of these improvements occurred on the HSR sections. The safety effect of the ATM system was also evaluated using data from 2016 for basic freeway segments in the corridor. The empirical Bayes methodology was used with Virginia statewide safety performance functions for freeway segments to quantify the safety impacts. The evaluation results showed 6%, 10%, and 11% reductions in total (all severity), multiple vehicle (all severity), and rear end (all severity) crashes, respectively. Segment-level analysis again showed that the most safety benefits were observed at locations with HSR (25%-40% crash reductions), and no significant reductions were found on the sections with only AVSLs and LUCS. This finding is consistent with the results from operational analysis.

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

18-02039

English

8p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

Figures; References; Tables

Highway safety; Highway traffic control; Interstate highways; Paved shoulders; Traffic crashes; Traffic lanes; Variable speed limits

Interstate 66

Northern Virginia

Highways; Operations and Traffic Management; Safety and Human Factors

Transportation Research Board Annual Meeting 2018 Paper #18-02039

TRIS, TRB, ATRI

Jan 8 2018 10:30AM