New Methodology: Permit Checking of Vehicular Overloads

Vehicular overloads are essential for economic activities, but the circulation of very heavy vehicles involves serious concerns regarding the structural safety of bridges. In most countries, the necessary permit process is time and cost consuming and the evaluation criteria sometimes do not lead to safe situations. This paper presents a new methodology for permit checking of vehicular overloads, based on an initial statistical study performed to characterize these vehicles. The method includes software that performs a simplified structural safety analysis of the bridges crossed by a vehicular overload, computing safety factors that compare code design load effects with those due to vehicular overload. The software also connects the vehicular overload database with a geographic information system representation of the highway network, allowing for the definition of several functionalities that support the permit decision. This new methodology allows for prompt, economical, and safe decision making on permit checking of vehicular overloads and is presently applied by the Portuguese national major expressway authority.