BACKGROUND

In the last 10-plus years, a significant body of research related to the geometric design of highways and streets has been completed (and many other projects are in process) and has had a direct and noteworthy impact on geometric design practice in the United States. 

This success can be attributed to the outcome of the strategic agenda published in NCHRP Synthesis 299: Recent Geometric Design Research for Improved Safety and Operations, Transportation Research Circular E-C110: Geometric Design Strategic Research, and NCHRP Synthesis 432: Recent Roadway Geometric Design Research for Improved Safety and Operation.

The next 10 years of road and street design research will be a time of great change and innovation in our industry. This includes strategic approaches to multimodal integration and performance- and context-based design. A renewed strategic research agenda for geometric design is needed to guide future research topics, priorities, and investments.

OBJECTIVE

The objective of the project is to develop a strategic research agenda to support state DOTs in guiding and advancing the practice of human-centered multimodal design of highways, roads, and streets in the United States. 

The outcome of this research will be a renewed strategic research agenda for geometric design of highways and streets. The strategic research agenda will help establish priorities and investment areas and will achieve the following:

• Identify, review, and summarize key geometric design research presented and published in the last decade by the TRB, the NCHRP, the FHWA, state DOTs, and universities. 
• Identify areas where a multifaceted or interdisciplinary approach to research can harmonize with well-accepted geometric design publications (e.g., the Green Book and other AASHTO publications).
• For the topics identified during the literature review, determine to what extent the recommendations or findings were incorporated into the current version of well-accepted geometric design publications and what questions remain unanswered or what additional research should be done to advance the state of the practice and inform future editions of geometric design guidance.
• Investigate the origin and basis of the guidance presented in the well-accepted geometric design publications, evaluate its validity relative to human-centered multimodal systems and its proven performance effects, and determine what additional research is needed.
• Ensure that the guidance in AASHTO's two resolutions (2016 and 2022), the Green Book (8th ed.) vision statement, and findings from NCHRP Research Report 839 Section 3.2 are considered as part of the above evaluations, i.e., verify that the current well-accepted geometric design publications fully address the recommendations around flexibility, performance- and context-based design, multimodal integration, etc. This includes coordination with the project panel and contractor of NCHRP Project 07-29, “Development of the 8th Edition of AASHTO's A Policy on the Geometric Design of Highways and Streets (Green Book)” (if that project has not yet concluded) to identify potential gaps to be incorporated in future well-accepted geometric design publication editions.
• Assess the needs and priorities of the stakeholder and practitioner community related to geometric design research through surveys, focus groups, and workshops with subject-matter experts representing state highway agencies, local (county/city/municipal/tribal) agencies, academia, the private sector, and TRB committees (representing perspectives that inform design for all users).
• Identify topics that have not been studied or researched that should be considered as part of an updated strategic research agenda in cooperation with the TRB Performance Effects of Geometric Design committee (AKD10) and the AASHTO Technical Committee on Geometric Design (TCGD).
• Establish guiding principles for research projects that address empirical performance data to the extent feasible.
• Incorporate other emerging topics, including: 
  • the implementation of the Safe System approach in the United States
  • policies concerning climate change and transportation system resiliency
  • the continuation and maturation of the context classification
  • multimodal approaches to planning and design that rely on more sophisticated data-driven models to inform design decisions
  • the ability to exercise appropriate professional engineering judgment when it comes to flexibility in design
  • evolving vehicle types
• Recommend means and methods for creating and maintaining a curated database of relevant completed and ongoing research. 

RESEARCH PLAN

The research plan should build in appropriate checkpoints with the NCHRP project panel, including at a minimum (1) a kickoff teleconference to be held within 1 month of the contract’s execution date to validate and refine the final scope, format, and deliverables, (2) at least one face-to-face interim deliverable review meeting, and (3) web-enabled teleconferences tied to panel review and/or NCHRP approval of interim deliverables.

The research plan will describe appropriate deliverables (which also represent key project milestones), including:

• An interim report and panel meeting. The interim report should include the analyses and results of completed tasks, a plan for the remaining tasks, and a detailed outline of the final research product(s). The panel meeting will take place in Washington, DC, after the panel review of the interim report. The interim report and panel meeting should occur after the expenditure of 40 to 50 percent of the project budget. No further work is allowed until the interim report is approved by the NCHRP. 
• A final research report documenting the entire research process.
• A strategic research agenda that sequences and prioritizes the research topics based on state DOTs’ immediate, short-term, and long-term needs.
• A technical memorandum titled “Implementation of Research Findings and Products”.
• A slide deck presenting the research findings and conclusions, to be used in webinars.

STATUS: Proposals have been received in response to the RFP. The project panel will meet to select a contractor to perform the work.