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SWUTC Research Project Description

An Integrated Approach to Managing the Transportation Systems

University: University of Texas at Austin

Principal Investigator:
Zhanmin Zhang
Department of Civil and Environmental Engineering
(512) 471-4534

Project Monitor:
Dr. Michael R. Murphy
Center for Transportation Research
The University of Texas at Austin

Funding Source: USDOT and State of Texas General Revenue Funds

Total Project Cost: $75,900

Project Number: 600451-00089

Date Started: 1/1/13

Estimated Completion Date: 12/31/13

Project Summary

Project Abstract:
The efficiency of our transportation system, particularly its highways, is critical to the health of the state’s economy.  As Texas becomes the nation’s second largest economy, businesses are increasingly reliant on an efficient and reliable transportation system to move products and services.  However, the gap between projected revenues and minimum investment needs average several billions per year. Under this situation, finding proper funding strategies and levels for maintenance of pavements and bridges in Texas requires fresh perspectives by looking at the problem not only in terms of maintenance itself, but also in terms of finance and operations.  The objective of this project is to fine-tune the framework for an integrated approach to managing the transportation systems.

Project Objectives:
The objective of this research is to fine-tune the framework of an integrated approach to better manage the Texas transportation system under limited funding, where a multi-tier management system were established. The fine-tuned framework will allow resources to be allocated among tiers according to their level of service and performance goals. Moreover, a user-fee backed public finance mechanism is also part of the proposed system. In addition, we will also propose an optimization method to address infrastructure deterioration and mobility problems together.

Task Descriptions:

Task 1.  Synthesize Literature
A literature review will be conducted to investigate the state of the art in managing transportation systems. The methods employed by other state DOTs and international organizations will be evaluated against their applicability in Texas. Although considerable literature on this subject has been reviewed during the preparation of this proposal, a further review of recent efforts will help the research proposed. All the information obtained from the literature review will be carefully categorized, systematically analyzed, and thoroughly documented.

Task 2.   Fine-Tune the Multi-Tier Networks
A single-tier system can work very well if the resources are sufficient to cover the entire network. However, when resources are constrained, hard decisions must be made in terms of which element of the road network should be given the priority first and which the last. In this task, we will fine-tune a multi-tier system for Texas road network based on the relative importance of the road links in the network, where the resources are tilted more towards the road group or tier that is deemed to be the most important. To conduct the multi-tier analysis, the first step is to define the tiers, using criteria such as highway functional class, ADT, truck ADT, etc.

Task 3.   Fine-Tune Criteria for Defining the Backbone, Backup, and Connection Systems
In this task, the criteria for defining the Backbone, Backup, and Connection systems will be fine-tuned.  The Backbone system is expected to serve as the critical connections among major economic centers in Texas.  For example, Interstate 10 through the southern part of the state, Interstate 20 from east of the Dallas-Fort Worth to Interstate 10 near Midland, along an extended Interstate 27 through western Texas, and a new terrain corridor along the northern Texas border paralleling sections of Interstate 30 from the Arkansas line at Texarkana to Fort Worth, US-287 from Fort Worth to Amarillo, and Interstate 40 from Amarillo to New Mexico. The level of service of the Backbone system will be defined as “Premier”, which means all goal criteria a (safety, mobility, dependability, and comfortability) should be fully satisfied. The Backup and Connection road systems are defined as the supplement to the Backbone systems, with the Backup system providing “Standard” level of service, and the Connection system giving the “Basic” level of service. The required level of services for the Backup and Connection systems are not as strict as that of the Backbone system.

Task 4. Fine-Tune Performance Measures for Different Levels of Service
In this task, we will fine-tune specific performance measures for different levels of service to gauge the impacts of the decision making process on the transportation system. The performance measures to be developed will focus on the same set of goal areas outlined in the previous task, including safety, mobility, dependability, and comfortability. The rationale behind this performance-based approach to transportation system management is to establish a few overarching goals and identify supportive performance measures within each goal area that the TxDOT could incorporate into its transportation planning process.

Task 5.   Fine-Tune the User Fees
In this task, we will Fine-Tune a user-fee backed public finance to be considered as potential solutions to ensure a dedicated revenue source for transportation infrastructure and to provide congestion relief through demand-based pricing. Direct user fees, or tolls, on the usage of the Backbone system is a promising solution to Texas’s problems of insufficient funding and congestion in the transportation sector. Tolling offers a dedicated revenue source that would be usage based, more reliable and, if appropriately structured, less susceptible to political intervention. With a dedicated revenue source in place, it would become much easier to finance Texas’s roadways through the issuance of revenue bonds.  It is important to point out that, since a Backup system paralleled to the Backbone system is available for the general public to use without any additional fees, the choice of using the Backbone system with an additional user fee is “voluntary,” but NOT “forced.”

Task 6.  Fine-tune the Framework for Optimizing Funding Balance between Infrastructure Preservation and Mobility Projects
In this task, we will fine-tune the methodological framework for the optimal selection of infrastructure preservation and mobility projects under limited budget. It can be argued that infrastructure preservation and mobility enhancement are the two major investments in transportation systems. Infrastructure preservation projects improve existing infrastructure conditions, whereas mobility enhancement projects include scenarios of adding new links to the network, expanding existing links and so on. In the current funding allocation process, these two investments are usually considered separately.

Infrastructure preservation problems are generally formulated as multi-period, resource allocation problems with additional constraints representing the infrastructure deterioration process. The objective for this type of problem resolution is usually to maximize infrastructure condition during the planning horizon under budget constraints or to minimize total cost incurred while satisfying a given condition goal. Mobility enhancement problems are mostly formulated as single-period, bi-level, network design problems to minimize travel time. Although infrastructure preservation and mobility enhancement problems are normally solved separately, they can be interrelated when the goal is to optimize overall system performance. Accordingly, it is necessary to consider those two problems concomitantly. Suppose that preservation and mobility projects selected from a pool of projects are carried out each year, then decisions should be made to maximize overall system performance and satisfy budget constraints.

Task 7.  Prepare Project Report
Every effort will be made to document the findings of the research.  At the end of the project, the research team will prepare a comprehensive report documenting the findings in an integrated approach to managing the transportation systems.

Implementation of Research Outcomes:
Asset valuation has become a key component in asset management because it links the performance of infrastructure and deterioration process with the value of the infrastructure and its depreciation, providing critical information for decision makers at various levels to make more informed decisions. This research presents a utility-based methodological framework for the valuation of transportation infrastructure along with a case study to demonstrate its applicability. The proposed framework can assist state and local transportation agencies in the optimization of resource allocation procedures for better coordination of asset investments, facilitating benefit-cost analyses to quantify the impact of infrastructure investments.

Products developed by this research:

New Method Developed:  A new method for transportation asset valuation.

Presentation:  An Integrated Approach to Managing the Transportation System:  Study  Results, Zhanmin Zhang, presented to the ASCE T&DI 2nd Congress, Orlando, FL, June 8-11, 2014.

Presentation:  A Novel Utility-based Methodological Framework for the Valuation of Road Infrastructure, Zhanmin Zhang, presented at the 94th Transportation Research Board Annual Meeting, Washington, D.C., January 2015.

Impacts/Benefits of Implementation:
The developed methodology for transportation asset valuation will allow a value tag to be attached to any segment of a highway for communicating the information to the general public and supporting decision makings by the highway agencies.

Web Links:
Final Report