Determining Guidelines for Ramp and Interchange Spacing

Download or read book Determining Guidelines for Ramp and Interchange Spacing written by and published by . This book was released on 2010 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project considered the effects of geometry, traffic operations, safety, signing, and other factors to develop guidelines for understanding the considerations that influence minimum ramp and interchange spacing values. Phase I included conducting a literature search and other information gathering activities, developing a work plan to assess the impact of ramp spacing on traffic operations and safety, and developing a framework for the research guidelines. Phase II included creating microscopic simulation models of closely-spaced ramp combinations calibrated with field data, constructing a crash database and developing crash prediction models, developing a set of guidelines for ramp and interchange spacing, and recommending changes to major resource documents within the transportation profession. As a final product, the team wrote NCHRP Report 687, "Guidelines for Ramp and Interchange Spacing," to assist users as they consider new or modified ramps and interchanges.