01628719

Component

The study presented in this paper aims at examining the effects of the advisory VSL system along OR 217 corridor in Portland, Oregon on the fundamental traffic flow diagrams. This system is part of the OR 217 active traffic management project and is intended to proactively manage vehicle speeds and improve reliability and safety along this urban freeway corridor. A before-and-after study was conducted using data from two sites in the northbound and southbound directions. The flow-occupancy diagrams at the study sites were examined before and after the deployment of the VSL system under different times of day, days of week and weather conditions. The results showed that the advisory VSL system notably affects the shape of the flow-occupancy diagrams and that the effect is more evident in the congested region. The flow-occupancy diagrams also confirm the effectiveness of the system in lowering average speeds along the corridor. Further, results suggest that the advisory VSL activation may result in reduced capacities as was evident in almost all the scenarios examined in this study.

This paper was sponsored by TRB committee AHB45 Standing Committee on Traffic Flow Theory and Characteristics.

01618707

17-04095

English

20p

2017

Transportation Research Board 96th Annual Meeting

Digital/other

Figures; References; Tables

Before and after studies; Highway capacity; Urban highways; Variable speed limits

Fundamental diagram

Portland (Oregon)

Highways; Operations and Traffic Management

Transportation Research Board Annual Meeting 2017 Paper #17-04095

TRIS, TRB, ATRI

Dec 8 2016 11:34AM