This report describes a survey of current practice as well as analysis performed to develop guidelines for agencies which need load restrictions during spring thaw periods. The results show for a range of locations in the U.S. and Canada that the average load restrictions applied is about 44 percent. The analysis performed in the study tends to confirm that level of load restriction. Further, it was found for the assumed conditions that a minimum load restriction level (if any load reduction is needed) is about 20 percent. Load restrictions greater than 60 percent are generally not warranted for the range of cases studied. An air temperature based criterion (Thawing Index) was developed which can be used to estimate when to apply and remove load restrictions.
August 19, 2007
Joe P. Mahoney, Mary S. Rutherford, R. Gary Hicks.
Washington State Transportation Center (TRAC), University of Washington. Dept. of Civil Engineering.
- # of Pages: 47 p., 851 KB (PDF)
- Subject: Atmospheric temperature, Axles, Bearing capacity, Deflection, Freeze thaw durability, Frost damage, Frost heaving, Guidelines, Highway travel, Impact loads, Load limits, Pavement performance, Spring, Structural deterioration and defects, Thaw, Tires.
- Keywords: Load restrictions, frost, thaw, tire, axle, spring thaw, thaw weakening.
- Related Publications: Guidelines for Spring Highway Use Restrictions, (WA-RD 80.1).
This abstract was last modified April 29, 2008