Congestion Relief by Travel Time Minimization in Near Real Time

Principal Investigators

Dr. Charles R. Standridge
Grand Valley State University

Co-Investigators

Dr. Shabbir Choudhuri
Grand Valley State University
Dr. Snehamay Khasnabis
Wayne State University

Project Dates:

11/22/2006 to 05/31/09

Project year: Year 2

MIOH-UTC Project Identifier: TS 1; Projects 1, 2 and 3

Focus Area:

Research: Intelligent Transportation Systems

Abstract:

The development and validation of near real-time methods, procedures, and software to reduce congestion in a traffic corridor is the focus of this project. Reducing traffic density, which relieves congestion, can be accomplished by reducing travel time for a given flow, the demand for travel in a corridor. Effectively using the capacity of the entire corridor will be necessary to reduce travel time.

Reducing travel time between an origin and a destination is accomplished by selecting a route through a corridor, perhaps consisting of portions of multiple networks, given current information about the corridor. This selection depends on the current conditions in the corridor. Information concerning these conditions would be provided by an intelligent transportation system (ITS). Information about which route (or routes) would result in the shortest travel time could be returned to individuals through the same system. The determination of the best route(s) would be done in near real time.
In addition, travelers rely on the consistency of travel times and routes in their daily living. Thus, keeping the capacity of a transportation corridor as near to constant as possible appears helpful.

To address these requirements, a project with three main tasks is proposed.
Project Scheduling to Level Corridor Capacity Task: Scheduling of construction and other projects that reduce the capacity in a corridor will be performed such that capacity is as constant as possible. Constraints such as the following will be taken into account:

The same equipment or personnel must serve multiple projects.
Some work must only be done during certain times of the year.

Static / Dynamic Route Selection Algorithms with Validation by Simulation Task: Existing algorithms for route selection will be reviewed, implemented, and tested in selecting a route selection algorithm. Optimization algorithms to select a route under steady-state or static conditions are well known and have been implemented in generally available commercial applications such as GPS systems and MapQuest. Optimization algorithms that select the shortest route under dynamic conditions and interface in near real-time with an ITS appear to require additional research, development, and implementation.

A simulation model of a traffic corridor, including all networks in the corridor, is essential to this effort. The level of detail: macroscopic, microscopic, or mesoscopic required in the simulation model that is necessary to make traffic routing decisions will be determined.

Data and Model Fusion: Raw data received from an ITS, or data generated to represent that received from an ITS, will be processed into a form suitable for input to the simulation and optimization models. Capabilities for sending information, such as routes, to an ITS will be provided.
A demonstration of the effectiveness of the capabilities of the software environment will be performed using either the integrated corridor from the Detroit suburbs (Novi, Troy, Dearborn, etc.) to downtown Detroit or the US 131, I-196, I-96 corridor from the environs of Grand Rapids to downtown.
The overall objective of this project is to provide near-real time information to travelers to help them minimize their travel time. Minimizing travel time will minimize congestion in a corridor. The year one objective is to demonstrate that effectively meeting this objective is feasible. Doing this includes:

Identifying, developing, and implementing route selection algorithms, both static and dynamic, as well as showing their effectiveness using traffic corridor simulation.
Identifying, acquiring, and fusing available ITS data to support the route selection models as well as showing via simulation the effectiveness of supplementing such data with simulation results.
Identifying how route selection information can be transmitted to travelers via an ITS.
Showing that corridor capacity can be kept relatively constant by the effective scheduling of construction and other projects that disrupt corridor capacity.

Accomplishing the year one objective will require the development of the following tangible items.

A state-of-the-art literature review in the area of dynamic route selection.
A state-of-the-art literature review with regard to the information currently available from ITS systems as well as short and medium term plans for acquiring and providing additional information through such systems.
A validated simulation model of a traffic corridor of interest, either in the Grand Rapids area or the Detroit area.
A dynamic route selection model integrated with the simulation model.
A model to schedule projects that disrupt corridor capacity that seeks to keep corridor capacity as constant as possible.
Methods, procedures, and software for acquiring, managing, and integrating ITS data with the simulation and dynamic route selection models.
Methods, procedures, and software for managing the quantitative results of all models as well as making these results available to all of the models and an ITS system.
An integrated software environment that includes all models as well as the data fusion activities described in the previous two objectives.

The year two objective is to integrate the algorithms and procedures developed in year one into an operational ITS and show their effectiveness in travel time minimization and congestion relief.

This project addresses congestion relief, which is the top priority from the political leaders of the US Department of Transportation and is included in the SHRP II initiative. Transportation is viewed as taking place in an integrated corridor, which is consistent with the Integrated Corridor Management Initiative of the Federal Highway Administration (FHWA). This effort deals with what information an ITS should provide to travelers and how to provide that information to the ITS. This is consistent with the real time traveler information systems effort of the FHWA.

This project is consistent with and makes use of the ITS proposal developed by SEMCOG. We will work with SEMCOG, M-DOT, and governmental agencies in the Grand Rapids area to obtain data on construction and other projects as well as to determine scheduling constraints and to seek help in model validation.