MPC
Research Projects (2007-08)

Identifying Number

MPC-290

Project Title

Evaluation of Transit Signal Priority Strategies for Bus Rapid Transit Project on 3500 South Street in Salt Lake County, UT

University

University of Utah

Principal Investigator

Aleksandar Stevanovic

Description of Project Problem

Evaluations of Bus Rapid Transit (BRT) deployments across the USA have shown benefits of the BRT projects in alleviating traffic congestion. Wasatch Front Regional Council (WFRC) (a local Metropolitan Planning Organization) incorporated several BRT projects in the regional transportation plan from 2007 to 2030. Utah Transit Authority (UTA) will implement the first regional BRT project in 2008. The BRT will be deployed along 3500 S, one of the major arterials, which connects fast-growing western part of the county with major N-S highway and transit routes (I-15, I-215, Sandy-Salt Lake Light Rail line, etc.). Purpose of this project is to evaluate benefits of the first BRT installation in the Salt Lake County.

Project Objectives

1. Define criteria for evaluating benefits of BRT installation on 3500 S
2. Design a BRT evaluation through traffic micro simulation
3. Develop alternative strategies for Transit Signal Priority (TSP) for the BRT line
4. Perform analysis of "Before BRT" and "After BRT" conditions

Project Approach/Methods

VISSIM microsimulation software will be used to build high-integrity models of traffic and transit conditions before and after BRT implementation. UTA, Utah Department of Transportation (UDOT), and WFRC will provide traffic and transit data to input into the models. VISGAOST, new optimization software developed by Utah Traffic Lab, will be used to investigate various TSP strategies for the BRT line. VISGAOST is a program which uses a Genetic Algorithm to optimize signal timings based on their evaluations in VISSIM. The TSP settings can be optimized together with basic signal timings (thus minimizing user delays regardless of the transportation mode) or separately – to give priority to BRT users. It is the first optimization tool which can optimize TSP settings.

Contributions/Potential Applications of Research

The BRT implementation on 3500 S is the first BRT project in the region; thus representing a local showcase which may have significant impact on the other planned BRT projects in the region. This study will assess, mostly through microsimulation, operational benefits of such an implementation. Findings from the study, hopefully positive, will accelerate the other public transit and multi-modal projects planned for the near future. A method proposed to optimize the TSP settings for the BRT line has not been applied before in the similar projects. The VISGAOST tool represents a missing link in the optimization of the traffic control settings on arterial streets. Its application in this study will likely generate signal timings under which riders on the newly introduced BRT line will enjoy priority without causing significant disruption for private vehicles.

Time Duration

July 1, 2007 – June 30, 2008

Annual and Total Project Cost

$22,426 Total: $53,866

TRB Keywords

Transit, congestion, signal priority systems