Truck weight, dimension, and speed data are required for a wide variety of purposes, including maintenance management programs, pavement and bridge management systems, pavement and bridge design, cost allocation studies, and for compliance with FHWA-mandated vehicle weight and speed monitoring programs. Current methods for collecting these data are very costly to both the states and the trucking industry and are often ineffective. A technique is needed to economically acquire information on the characteristics of heavy vehicles and to provide a data base that can be used for improved planning, design, and maintenance of highways and bridges. The objective of this research was to develop a low-cost bridge weigh-in-motion (WIM) system capable of providing the traffic data used in the design and maintenance of highways and bridges. The system shall use state-of-the-art technology, have a target purchase price of $5,000 to $10,000 per unit, have a low life-cycle cost, be capable of interfacing with automatic vehicle identification (AVI) equipment, and be deployable on both bridges and large culverts.

The first phase of the research effort included (1) a review of existing bridge WIM/AVI systems, (2) development of a conceptual system design defining the data requirements, equipment performance criteria, hardware and software requirements, and estimated purchase price, (3) the development of a test system capable of collecting data for the gross vehicle weight for vehicles over 12,000 pounds, the number of axles and spacing, traffic counts of all vehicles, speed, and vehicle classification, and (4) laboratory tests to evaluate the system performance and capabilities. Based on the results of these efforts, in the second phase an improved prototype of the WIM system was constructed for general applications for different types of bridges and culverts considering environmental factors, installation and maintenance requirements, and vandal resistance
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Status: The final report was approved, but a decision was made not to publish it. An evaluation of the system has been conducted by the FHWA and the results are documented in an FHWA report.