Truck Platooning Impact on Bridge Preservation

Abstract

Truck platooning is a futuristic transportation system that is being explored by many countries and several states in the United States in a collaborative environment among stakeholders through on-road pilot testing and actual platooning. However, there are hundreds of thousands of bridges in the United States alone that have not been designed for this new loading. Per AASHTO methodology, bridge design is based on a notional live load model comprised of one or two trucks per lane in conjunction with or separate from an applied uniform load. Platoons with 3+ multibrand trucks per platoon are proposed to be the norm in the year 2025. An extensive literature search indicated a lack of published work that deals with the effect of truck platooning on the integrity of the superstructure–substructure system. This paper attempts to elucidate and illustrate the impact of truck platooning on the performance and integrity of existing bridges. Based on examples for continuous and simple-beam (stringer or girder) bridges, it is demonstrated that the live load of truck platoons would subject the components of the superstructure and foundation to straining actions that are several times higher than allowed by their current load rating. A case study representing a typical scenario for truck platooning is provided to shed light on the impact of platooning on the foundation of an existing bridge. The results clearly demonstrate that a reduced integrated bridge load rating should be anticipated for truck platoons compared with the conventional single or two truck patterns commonly used in practice. The data presented in this paper provide guidance and a preliminary tool for practicing engineers assessing the impact of truck platooning on existing beam (stringer or girder) bridges. It shows that truck platooning will necessitate new policies, regulations, and standards for both new and existing bridges. If preservation and reuse are to be considered preferable to replacement, implementation of new approaches regarding existing structures will be particularly important. The use of an integrated bridge load rating approach is recommended. Whereas the methods of superstructure load rating will vary with the bridge type, the concepts related to the substructure load rating as outlined in the paper remain valid for other types of bridges. However, additional work is needed to substantiate implementation to other bridge types. To streamline all facets of structure maintenance, and to ensure quality control/quality assurance, the authors also advocate the creation of a holistic type of maintenance contract called maintenance engineering and inspection, rather than the push-button contracts more commonly used in the asset management arena.