MTC Asset Newsletter Summer 2005

New Research in Progress for 2005

Asset Management Strategies to Mitigate Freeway Work Zone Congestion

Tom Maze (Iowa State University)

Identifying strategies to relieve work zone congestion on freeways is the primary objective of this project. The end result will be a decision matrix that incorporates strategies and various attributes of work zones. Examples of good practices based on these strategies will be stratified by type of project, e.g., urban interstates versus rural, long-term versus short-term work zones, interstates serving commuter traffic versus heavily used intercity routes.

Development of Fatigue Design Procedures for Slender, Tapered Support Structures

Brent Phares (Iowa State University)

Tall, slender support structures such as light poles are susceptible to two critical types of wind loading: natural wind gusts or buffeting and vortex shedding. Vortex shedding is a unique type of wind load that creates areas of positive and negative pressures alternately, causing the support structure to vibrate in the direction transverse to the wind direction. When the vortex shedding frequency approaches the natural frequency of the structure, the frequencies can cause greatly amplified displacements and stresses.

The goal of this project is to further understand the phenomenon of vortex shedding and buffeting in slender-tapered high-mast luminary support structures. Although a great deal of effort has been made during recent years to improve the analytical models used for predicting fatigue failure due to vortex shedding excitation, these models still need further refinement because they fail to accurately capture the effects of this phenomenon.

An Integrated Systems Approach to the Development of Winter Maintenance / Management Systems

James Noble (University of Missouri–Columbia)

Many state DOTs and other governmental units have adopted "bare pavement winter maintenance" policies with an interest in improving highway safety. These policies have resulted in improved snow plows, GPS tracking, anti-icing technologies, heated bridge decks, routing algorithms, and more. However, missing from the arsenal of winter maintenance/snow management tools is an integrated systems model for winter maintenance system design and operation. This project will bring systems engineering concepts into the process. This research proposes, through systems analysis, to design a winter maintenance system that takes into account the criteria that are important to DOT decision makers to provide a system that is efficient in terms of operations and asset management.

Secondary Accident Data Fusion for Assessing Long- Term Performance of Transportation Systems

Carlos Sun (University of Missouri–Columbia)

Secondary accidents are accidents that result from an existing primary incident. Often these accidents occur at the end of queues that resulted from the primary incident. Quickly opening the highway after an incident reduces the potential for secondary accidents.

In order to use secondary accidents as a performance measure, it is necessary to first separate such accidents from the rest of the database. Since the effect of primary accidents can persist long after a roadway has been cleared, it is difficult to determine at the scene of an accident if it is due to recurrent or non-recurrent congestion. By analyzing individual traffic reports in detail, the reporting times of the incident and the dynamic locations of the back of the queue can be found. This project proposes the use of data fusion of intranet traffic reports with the accident database, and will result in a near-term technology for analyzing the safety impacts of transportation assets.

Determining the Costs of Truck Transit Delays for Shippers of Freight: An Exploratory Study

Mike Crum (Iowa State University)

Knowledge of truck transit delay costs is important to transportation policy makers. There are problems with the traditional means for estimating these costs, however, as they typically focus on the operating and capital costs for the carriers and the in-transit inventory costs for the shippers. Many shipper costs are not captured by these approaches (e.g., cost of lost sales, cost of production delays). The primary purpose of this project is to explore and demonstrate the applicability of conjoint analysis for determining the cost of truck transit delays for shippers of freight, or conversely, the value of avoiding transit delays for shippers.