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South Dakota Department of Transportation
Project Synopsis

Title: Determination of Spring Load Restrictions
Project Researcher: Tom Wilson,
Project Manager: Dan Strand
Research Period: -
Cost: $0.00

Problem Statement:Each spring, certain state and county highways impose load and speed restrictions during the spring thaw period, when the pavements underlying base and subgrade support are reduced. Decisions regarding the start and duration of restrictions are made subjectively on the basis of weather and pavement condition observations. Due to the subjectivity of the decision, it is likely that some highways are posted or not posted, inappropriately. Determining the severity of the restrictions is also difficult.

Research is needed to develop objective methods for determining whether to impose restrictions on a given highway, when the restrictions should be imposed and lifted, and the nature of the restrictions. Methods for implementing spring restrictions must be developed to provide adequate advance warning to commercial carriers and maintenance forces.


Research Objectives:
1  Identify procedures to determine the need, start, duration, and type (load and/or speed) of restrictions..
2  Develop practical guidelines for application of restrictions.

Research Tasks:
1  Meet with the Technical Panel to discuss the research topic.
2  Review and summarize relevant literature to determine previous work, policies and/or procedures from other sources.
3  Interview other states that use spring restrictions concerning implementation and effectiveness of their imposed restrictions.
4  Interview county superintendents, commercial carriers, and department field personnel as to the application of spring restrictions.
5  Evaluate and summarize existing literature and data regarding the effectiveness of load versus speed restrictions.
6  Develop procedures to predict the need, start, duration, and type of restriction based on weather forecasts, deflection, temperature, and/or moisture data.
7  Submit a final report, including an executive summary, summarizing the literature, research methodology, findings, conclusions and provide recommendations for implementation of a spring restriction policy with load and/or speed restrictions.
8  Present findings and conclusions to SDDOT Research Review Board upon completion of the project.

Documents Available:

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