摘要: |
A variety of intersection control evaluation processes and metrics are used by highway agencies for evaluating intersection geometry and control alternatives and identifying an optimal geometric and control solution for an intersection. These processes usually address safety, operational, multimodal, environmental, right-of-way, and cost impacts and other considerations. However, there is no widely accepted procedure or guide for evaluating new intersections or modifications to an intersection.
There is a need to develop a guide that incorporates rational processes, objective performance metrics, and appropriate tools to provide a consistent and objective intersection control evaluation. Such a guide will help highway agency personnel in making decisions regarding intersection type and control, and implementing safer, more balanced, and more cost-effective solutions.
The objective of this research is to develop a guide for intersection control evaluation. The guide shall include associated processes and tools, and be prepared in a format appropriate for consideration and adoption by the American Association of State Highway and Transportation Officials (AASHTO). For the purpose of this research intersections include interchanges.
Accomplishment of the project objective will require the following tasks.
PHASE I: (1) Collect and review relevant domestic and foreign literature, research findings, and information relative to evaluating intersection control alternatives. This information may be obtained from published and unpublished information, and contacts with public and private organizations. (2) Based on the review performed in Task 1, identify the factors that are required for evaluating intersection control alternatives (e.g., geometric design, safety, operations, environment, and cost) and developing the guide.(3) Evaluate the factors identified in Task 2, identify and prioritize the weaknesses and gaps in available guidance, and identify those factors and gaps recommended for further consideration/investigation in Phase II: (4) Based on the evaluation performed in Task 3, prepare an updated, detailed work plan to be executed in Phase II that includes an approach for investigating the recommended factors and gaps and (a) develop rational processes for evaluating intersection control alternatives and (b) prepare a guide and associated tools for consideration and adoption by AASHTO. The plan shall also describe the proposed research and include a tentative outline of the proposed guide. (5) Prepare an interim report that documents the research performed in Tasks 1 through 4. Following review of the interim report by the NCHRP, the research team will be required to make a presentation to the project panel. Work on Phase II of the project will not begin until the interim report is approved and the Phase II work plan is authorized by the NCHRP. The decision on proceeding with Phase II will be based on the contractor's documented justification of the updated work plan.
PHASE II: (6) Execute the Phase II plan approved in Task 5. Based on the results of this work, propose processes and tools for evaluating intersection control alternatives. Also, illustrate use of the proposed processes and tools with examples covering a range of intersections and discuss how these processes and tools may be used for making decisions. Submit a technical report of the results and findings. (7) Develop the guide and accompanying tools. (8) Prepare a final deliverable that documents the entire research effort. The tools together with appropriate documentation and user manuals shall be incorporated in the proposed guide and presented as a stand-alone deliverable in a format suitable for consideration and adoption by AASHTO. |