Evasion of Weight-Enforcement Stations by Trucks

Abstract

Highway engineers have become increasingly concerned about the deterioration of the nation’s highway pavements. They suspect that overweight trucks are a primary cause of the problem. Before 1979, the data needed to assess the magnitude of the overweight-truck problem did not exist. Consequently, several studies were conducted to address the magnitude and location of overweight trucking. These studies included efforts to improve truck weight-enforcement programs and to assess the feasibility of using weigh-in-motion (WIM) equipment for weight enforcement. The Florida Department of Transportation (FDOT) undertook the study documented in this paper. The objective of the study was to assess the magnitude, expressed in equivalent single-axle loads (ESALs), of the problem of avoidance of weight-enforcement stations by overweight trucks. The study also considered whether bypassing traffic was local or interstate. FDOT selected the I-95 corridor in the northeast corner of Florida. Two permanent weight-enforcement stations and four bypass route locations were used as traffic monitoring sites. The results of the study indicate that the numbers of overweight vehicles decrease with increasing enforcement activity, but that vehicles attempt to bypass permanent truck weight-enforcement stations. In general, the violations at the permanent weight-enforcement stations were minor, whereas those on the bypass routes were much more severe. These results, when considered with the WIM data and the experience of truck weight-enforcement officers, suggest that only intensive enforcement activity can reduce violations to low levels. Information for enforcement, especially in the definition and quantification of the scale avoidance problem, is provided. Recommendations are made concerning corridor areas and extended and random enforcement operations.