Wisconsin large truck safety and enforcement study.

The Wisconsin Large Truck Safety and Enforcement Study (LTS&E) focused on a system-wide evaluation of large truck safety in the state of Wisconsin. This study analyzes crash data related to large trucks that are close to the following criteria: greater than or equal to 13 ft 6 in. in height, greater than or equal to 8 ft 6 in. in width, greater than 80,000 pounds and any truck at or longer than legal limits as allowed by Wisconsin Statutes chapter 348 for any and all legal length based on semi-tractor trailer combinations, that are operating with or without a permit in the state of Wisconsin and with or without exceptions as provided in either state statues or regulations. The crash data used during the development of this study is extracted from the WisTransPortal database of MV-4000 crash reports and additional MV-4000 data from the Wisconsin Truck and Bus data between 2004 and 2009. Part of this study includes the identification and analysis of the targeted large truck data in order to refine the amplitude of the project and to describe potential safety issues reflected by the historical crash data. Roadway characteristics and driver behavior seem to be the most significant variable in determining the severity of crash incidents. Certain features of roadway condition as well as driver factor might lead to an increase of certain type of crashes. Most harmful event was chosen over first harmful event as a potential predictor of crash severity, however, further analysis reveals that there is no striking difference in crash severity across different levels of most harmful event. Vehicle factors and highway factors were dropped from the model early in the analysis process as their composition does not seem to vary across different levels of crash severity.