Montana Department of Transportation

Malcolm “Mack” Long, Director


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Montana Weigh-in-Motion (WIM) and Automatic Traffic Recorder (ATR) Strategy

weigh in motion truck image A critical element in achieving the Montana Department of Transportation's fundamental goal of providing safe, efficient and sustainable transportation services is the collection of accurate data on how the state's highways are being used. Such data are necessary to supportweigh in motion truck image numerous MDT activities from planning, to infrastructure design, to enforcement of vehicle regulations. Due to limited resources, it is essential that such data are efficiently collected and then put to the best possible uses. The foundations of the data collection program are the permanent weigh-in-motion (WIM) and automatic traffic recorder (ATR) systems deployed across the highway network. Every WIM/ATR deployment, however, requires resources for installation, maintenance, and data reduction. Thus, a planning strategy is necessary to optimize MDT's investments in its WIM/ATR program.This project conducted a comprehensive review of MDT's WIM program along with a basic review of its ATR data collection program. The assessment encompassed both basic data collection activities as well as how these data are and can be subsequently used. In addition, the statewide traffic adjustment factors currently used by MDT were reviewed, and proposed regional adjustment factors developed that can reflect regional differences in highway use associated with changing demographics, economic conditions, and commodity flow.