The National Academies

NCHRP 08-163 [Pending]

Defining Appropriate Design and Accommodation Thresholds for Active Transportation in a Context-Driven Approach

  Project Data
Funds: $550,000
Contract Time: 24 months
Staff Responsibility: Jennifer L. Weeks


A common approach used in transportation design is to set minimum accommodations or guidelines, such as a minimum width, for a sidewalk or bikeway. Such guidelines provide for a basic level of infrastructure quality in cases where they are applied. The concept is also used at the planning level; for example, some Complete Streets policies specify minimum accommodations for pedestrians and bicycles. However, the minimum accommodations are frequently used as the default or preferred width in all cases, even though these widths often do not provide a level and quality that will significantly increase the use of walking, bicycling, and rolling, particularly among all types of users and in areas where greater walking, bicycling, and rolling activity is possible. Research is needed on the design flexibility and the different levels of accommodation recommended for different contexts and roadway types.


The objective of this research is to develop an active transportation guide and tool (or tools) that provide a decision-making framework for the adoption and implementation of supportive active transportation infrastructure and design ranges that provide better safety, comfort, and accessibility while still serving all surface transportation users and functions.

Accomplishment of the project objective will require at least the following tasks.


Task 1. Conduct a comprehensive literature review that addresses accommodations for active transportation in facility design as well as specific examples of design ranges and values, guidelines, tools, and decision-making techniques adopted or applied by transportation practitioners in the United States and internationally. Seek information regarding the impact of various designs on different roadway functions, uses, and users.  

Task 2.  Conduct broad practitioner engagement through a survey or other means proposed by the research team. The engagement should strive to identify and discuss the application and effectiveness of various roadway design policies, guidelines, practical approaches, tools, and methods adopted by agencies across diverse geographic and transportation contexts that provide flexibility in road and right-of-way design to achieve better safety, comfort, and level of service for active transportation. 

Among the issues to explore in the outreach are: 

  • The specific conditions, including different land uses, rights-of-way, and roadway functions under which agencies apply flexible designs that accommodate different users;
  • The effects of different design policies, guidelines, practical approaches, tools, and methods on various roadway users with a focus on the implications for safer, more comfortable, and accessible active transportation. This would include users of diverse socioeconomic backgrounds, genders, ages, and abilities;
  • The benefits and costs of implementing and maintaining various design ranges and values on transportation performance of various modes;
  • The barriers that impede the implementation of flexible active transportation design in different contexts, including but not limited to internal agency policies and priorities; and
  • The specific needs or gaps in knowledge, data, methods, tools, and techniques that may facilitate a more balanced and flexible approach to roadway design to accommodate active transportation with other major transportation functions, e.g., freight and transit.


Task 3.  Prepare specific case studies of successfully integrated design flexibility in projects, identified through Tasks 1 and 2. Case studies should include a variety of project types, land uses, geographies, and roadway functions to the extent practicable. The case studies should seek information on the policies, practices, strategies, and funding sources applied towards implementing the projects.

Task 4. Based on the data collected in Tasks 1-3, assess how the implications of applying specific minimum design values adopted for different transportation modes has affected the safety, comfort, and accessibility of active transportation.

Task 5. Identify and evaluate various approaches, design flexibilities, and/or ways of communicating design approaches that better serve the safety and comfort of active transportation users while addressing the barriers to providing flexible or context-driven designs.  

Task 6. Prepare an interim report that documents the research conducted, conclusions drawn from the research, and outline the content and format of the final deliverables of this research.

Task 7.  Prepare draft guide, decision-making framework, tool(s), and other deliverables of this research. The deliverables are expected to include:

  • Performance criteria and qualitative, quantitative, and/or surrogate measures used in decision-making regarding the application of different active transportation design;
  • Ranges of active transportation design values and other accommodations;
  • Succinct communication materials targeting different audiences, such as executive offices, planning and design professionals, and members of the general public. The use of creative design and graphics is encouraged;
  • A conduct of research report that describes and documents the full research project; and
  • An implementation plan focused on the practitioner that markets and encourages adoption of the products of this research, including training materials, opportunities to present material in conferences and other venues, and potential opportunities for integration into industry design standards and guides.

 Task 8.  Prepare final deliverables for publication.


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


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