Thaw weakening and load restriction practices on low volume roads

Low volume roads subjected to seasonal freezing are highly susceptible to damage from traffic during midwinter and spring thaws. Such traffic-induced damage can be minimized by a variety of design methods; however, most are not economically feasible. As a result, loads are often restricted or prohibited during thaw-weakened periods. While this practice reduces road maintenance costs, the economic impact on industries that rely on continued heavy trucking can be significant. This report reviews the process of ice segregation and thaw weakening, and then discusses both quantitative and qualitative results from a survey on load restriction practices that was distributed to state departments of transportation (DOTs). Survey topics include state DOT load restriction practices, types and mileage of roads posted, methods for determining dates for imposing and removing load restrictions, enforcement of restrictions, and feedback from road users.