Can Spring Load Restrictions on Low-Volume Roads be Shortened without Increasing Road Damage?

Abstract

Major highways are designed to withstand heavy vehicles and high volumes of traffic year round. However, low-volume roads in seasonal frost areas are highly susceptible to damage from trafficking by heavy vehicles during spring thaw. Conventional practice is to place partial or full spring load restrictions on low-volume roads during spring thaw. This practice reduces road damage significantly. However, companies whose livelihood depends on trucking can suffer major economic losses as they await the removal of load restrictions. Using reduced tire pressure constitutes a less conventional technique that can reduce springtime damage. Reducing tire pressure generally appears to be less effective than reducing load. Nevertheless, it does appear that the load restriction window can be shortened in duration by implementing a reduction in tire pressure for a few weeks, starting toward the latter part of the standard spring load restriction period. With a mechanistic pavement design and evaluation model for seasonal frost areas, a critical combination of load and tire pressure reduction was developed; it contributes to optimizing the balance between minimizing springtime road damage and minimizing disruption to local economies caused by load restrictions. This analysis constitutes the first step in the development of simplified, general application guidelines for shortening the springtime load restriction window for a variety of pavement structures.