At-grade trail crossings have frequently been the sites of bicycle, pedestrian, and snowmobile crashes in Minnesota and throughout the nation. To date, many resources exist for use in the design of trails and intersections, such as the MnDOT Bikeway Facility Design Manual, while guidelines of traffic control at roadway-trail crossings are covered in the MN MUTCD. Resources on comprehensive guidance for safety treatments at roadway-trail crossings, however, are limited. The goal of this document is to synthesize best practices observed statewide in Minnesota and nationally in order to provide engineers and other transportation professionals with guidance on safety treatment applications at trail crossings. Following discussion of principles of user-friendly trail-crossing designs, this document provides a toolbox of categorized treatments which are widely used in the U.S. with discussion on each treatment. Importantly, a decision tree-based treatment selection methodology is developed for fast look-up and selection of appropriate treatments based on the conditions at a particular trail crossing. These conditions include urban/rural setting of the crossing, number of lanes of the crossed roadway, whether the crossed roadway is divided or undivided, the speed limit and average daily traffic (ADT) of the crossed roadway, and whether the crossing is a midblock or parallel path crossing. Each end node of the decision tree leads to a specific toolbox in table form containing all appropriate treatments for the conditions of the study trail crossing. Final treatments for the study site can be simply chosen from the table, combined with site-specific requirements and engineering judgment.
The degree of modal split in the United States has continued to change with increased use of non-motorized modes. To accommodate a variety of users, context-sensitive solutions are being pursued. Such solutions call for the sharing of right-of-way by multiple user groups with different and often competing demands. Traditionally, the needs of vehicular traffic have been prioritized as evident in many current design standards. This research focuses on developing guidance for design decisions to best balance the competing needs and accommodate all expected roadway users. Non-standard design solutions, often associated with complete streets, were investigated in two major contexts. The first involved a comprehensive review of the current-state-of-the-practice in design standards, complete streets, and associated legislation in Minnesota and nationally. Second, a detailed analysis of 11 'complete street' study sites was conducted. The study primarily focused on evaluating changes in safety and operations between the periods before and after implementation. Differences in the characteristics of the study sites and varying degrees of changes and improvements conducted at each site prevented an aggregate quantification of the implications of complete street improvements across all sites, and specific recommendations for changes in design standards. Nevertheless, the analysis of complete street designs implemented at the 11 study sites suggest that changes made to these study sites did not result in adverse safety or operational impacts. Therefore, providing flexibility and modification to the State Aid Design Standards in the context of complete streets and conditions specified in this research appears to be a reasonable consideration.