Benefit

Decision Support System scenarios modeled on the ICM Corridor in Dallas Texas show travel time savings of 9 percent on arterials when vehicles divert from the freeway.

Research using Dynamic Traffic Assignment applied to the Integrated Corridor Management (ICM) System in Dallas Texas.


August 1, 2012
Dallas,Texas,United States


Summary Information

This paper presents a real-time traffic network state estimation and prediction system with built-in decision support capabilities for traffic network management. The system seeks to provide traffic network managers with the capabilities to estimate the current network conditions, predict congestion dynamics, and generate efficient traffic management schemes for recurrent and non-recurrent congestion situations. In this case, the system is applied in the context of Integrated Corridor Management (ICM), to a section of a commuter corridor in Dallas, Texas. ICM is envisioned to provide a system-based approach for managing congested urban corridors, providing traffic network managers with decision support capabilities through developing efficient traffic management schemes that integrate a wide range of traffic control and traveler information strategies.

Of the numerous offline applications, simulation-based Dynamic Traffic Assignment (DTA) models have proved to be a valuable tool for modeling congestion dynamics in large-scale urban transportation networks. Thus, extensive research efforts have been devoted to extending the capabilities of these models for real-time traffic management applications.

METHODOLOGY

The study area includes a section of Dallas North Tollway (DNT) surrounded by parallel and perpendicular arterials. The network consists of about 400 links and 150 junctions. A demand pattern that approximately represents a typical evening rush period is considered. Four congestion levels are considered, low, medium, medium-high and high, respectively. DNT represents the principal freeway in the network and carries about two-thirds of the traffic in the northbound direction. The other one-third of the northbound traffic uses all parallel arterials. A simulation-assignment Dynamic Traffic Assignment (DTA) model is used to determine the user-equilibrium (UE) traffic flow pattern in the network for the entire horizon. Three scenarios are compared for a number of cases:
  • Normal operation conditions (no incident).
  • Travelers follow their historical routes and experience the delay due to the incident on the freeway while the traffic management system remains inactive.
  • The traffic management system is activated to manage the incident.
Assumptions made:
  • Travelers follow their historical routes and receive no pre-trip or in-vehicle information.
  • Travelers follow a user-equilibrium (UE) behavior.
In all scenarios, a traffic management scheme is assumed to consist of timing a subset of the signalized intersections along parallel arterials (30 intersections), and activating the DMS upstream of the incident on the Tollway (freeway). A genetic algorithm methodology is developed to generate efficient traffic management schemes that integrate preapproved control actions by all managing agencies. The diversion percentages range from 10 percent to 70 percent of the traffic on the freeway.

FINDINGS
  • A percentage savings in the average travel time over the entire network of about 9 percent is recorded for the case when traffic is diverted and all 30 arterial intersections are considered when compared to the do-nothing scenario.
  • In the case where only signalized intersections along the frontage road are considered, the saving in the average travel time over the network was limited to about 3 percent.
  • More spatial coverage allows improvement of the signal timing plans and increases the capacity of more diversion routes during the incident.
  • Improving the capacity of the diversion routes enhances the overall network throughput and results in more travel time saving.

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Source

Real-Time Traffic Network State Estimation and Prediction with Decision Support Capabilities: Application to Integrated Corridor Management

Author: Hossein Hashemi , Khaled Abdelghany, Ahmed Hassan, M. Maverick Lezar

Published By: Transportation Research Board

Source Date: August 1, 2012

URL: http://assets.conferencespot.org/fileserver/file/42725/filename/2vdv8k.pdf

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Goal Areas

Mobility

Typical Deployment Locations

Metropolitan Areas

Keywords

coordinated signals, signal coordination, centralized signal control, signal synchronization, traffic signals, advanced signal control, signal timing optimization, coordinated signal control, advanced signal controller, traffic signal retiming, retiming, DMS, CMS, VMS, Changeable Message Signs, Variable Message Signs

Benefit ID: 2013-00868