The primary focus of this synthesis is to document and summarize current practices relating to access location and design on crossroads in the vicinity of interchanges. In addition, this synthesis was designed to identify standards and strategies used on new interchanges and on the retrofit of existing interchanges. Each element of this synthesis is described in the fol-lowing paragraphs.
The synthesis includes a summary of literature on the current research and publications available in the area of access management on crossroads in the vicinity of interchanges. Within the discussion, the synthesis also provides additional resources to help readers obtain specific information about the planning, operational, and design elements associated with locating access points in the vicinity of interchanges. Discussion of the literature review per-tains to access management policies, summarizes various impacts of access management techniques, and addresses some of the tools for implementing an access management pro-gram.
In addition, the synthesis provides a summary of the strategies employed by various state departments of transportation, toll agencies, and other road authorities to manage access to and from crossroads in the vicinity of interchanges. The information presented is primarily based on questionnaire responses received from the various agencies, a review of additional materials provided by the agencies, and follow-up telephone interviews with the agency con-tacts. Based on these efforts, the synthesis includes a discussion on the survey questionnaire and design; survey responses and findings; agencies’ access management programs; spacing standards on interchange crossroads; factors influencing access location on interchange crossroads; spacing measurement on interchange crossroads; access management techniques for interchange crossroads; and planning, operation, and design practices for new and retro-fit interchange projects.
In addition to a discussion of some of the planning, operation, and design practices for new and retrofit interchange projects, the synthesis provides several case studies illustrating how various transportation agencies have dealt with access locations on interchange cross-roads through new and retrofit interchange projects. Based on the responses from the survey questionnaires sent to various agencies throughout North America, and on follow-up inter-views, eight case studies are summarized within the synthesis.
Although significant research has been conducted and much information has been col-lected on the benefits of managing and locating access points outside of interchange termi-nals, there are still impediments that continue to limit the ability of transportation profes-sionals to successfully implement these practices. These impediments can be and have been overcome by agencies that have solid access management legislation and/or regulations, and that employ integrated processes to plan, design, operate, and maintain interchange facilities and the downstream access location points on their crossroads. + Read more