Purpose of This Report
This report has been developed in response to widespread interest for improving both mobility choices and community character through a commitment to creating and enhancing walkable communities. Many agencies will work toward these goals using the concepts and principles in this report to ensure the users, community and other key factors are considered in the planning and design processes used to develop walkable urban thoroughfares.
Traditionally, through thousands of years of human settlement, urban streets have performed multiple functions. Mobility was one of the functions, but economic and social functions were important as well. Retail and social transactions have occurred along most urban thoroughfares throughout history. It is only in the 20th century that streets were designed to separate the mobility function from the economic and social functions. This report is intended to facilitate the restoration of the complex multiple functions of urban streets. It provides guidance for the design of walkable urban thoroughfares in places that currently support the mode of walking and in places where the community desires to provide a more walkable thoroughfare, and the context to support them in the future.
While the concepts and principles of context sensitive solutions (CSS) are applicable to all types of transportation facilities, this report focuses on applying the concepts and principles in the planning and design of urban thoroughfares—facilities commonly designated by the conventional functional classifications of arterials and collectors. Freeways, expressways and local streets are not covered in this report. The following chapters emphasize thoroughfares in "walkable communities"—compact, pedestrian-scaled villages, neighborhoods, town centers, urban centers, urban cores and other areas where walking, bicycling and transit are encouraged. Practitioners working on places and thoroughfares that do not completely fit within this report's definition of walkable urban thoroughfares may also find this guidance useful in gaining an understanding of the flexibility that is inherent in the "Green Book"—the American Association of State Highway and Transportation Officials' (AASHTO's) Policy on Geometric Design of Highways and Streets (AASHTO, 2004a).
Throughout this report, for brevity, the terms "principles of CSS" and "CSS" are used interchangeably.
CSS and This Report
The principles of CSS promote a collaborative, multidisciplinary process that involves all stakeholders in planning and designing transportation facilities that:
Applying the principles of CSS enhances the planning and design process by addressing objectives and considerations not only for the transportation facility but also for the surrounding area and its land uses, developments, economic and other activities and environmental conditions. With a thorough understanding of the CSS principles and design process, the practitioner planning or designing a thoroughfare seeks to integrate community objectives, accommodate all users and make decisions based on an understanding of the trade-offs that frequently accompany multiple or conflicting needs.
Applying the principles of CSS in the transportation planning or project development process identifies objectives, issues and trade-offs based on stakeholder and community input starting at the regional planning process and continuing through each level of planning and project development (for example, network, corridor and project). This report provides guidance in how CSS principles may be considered and applied in the processes involved with planning and developing roadway improvements for walkable urban thoroughfares.
As documented in Context-Sensitive Design Around the Country (TRB 2004), A Guide to Best Practices for Achieving Context Sensitive Solutions (TRB 2002) and other sources, the principles of CSS are successfully used in towns and cities as well as in rural areas. Agencies are transforming the current project development process to meet the expectations of all users and stakeholders. Integrating CSS principles into the project development process results in the consideration of a broad range of objectives and an attempt to balance these objectives based on the needs and conditions specific to each project and its context. The use of CSS principles in the project development process is resulting in community interests, user needs and environmental issues being considered early in the development of roadway improvement projects—specifically in defining the project's purpose and need and, as appropriate, in other decisions in each phase of the project.
Objectives of this Report
The objectives of this report are to
1. Identify how CSS principles can be applied in the processes (for example, network, corridor, project development) involved with planning and developing roadway improvement projects on urban thoroughfares for walkable communities;
2. Describe the relationship, compatibility and trade-offs that may be appropriate when balancing the needs of all users, adjoining land uses, environment and community interests when making decisions in the project development process;
3. Describe the principles of CSS and the benefits and importance of these principles in transportation projects;
4. Present guidance on how to identify and select appropriate thoroughfare types and corresponding design parameters to best meet the walkabil-ity needs in a particular context; and
5. Provide criteria for specific thoroughfare elements, along with guidance on balancing stakeholder, community and environmental needs and constraints in planning and designing walk-able urban thoroughfare projects.
Walkable communities are urban places that support walking as an important part of people's daily travel through a complementary relationship between transportation, land use and the urban design character of the place. In walkable communities, walking is a desirable and efficient mode of transportation. Although nearly every human environment can accommodate some degree of walking, walkable communities give additional value and support to make walking an enjoyable experience (see sidebar regarding the "continuum of walkability").
Principles for walkable communities include the following:
1. Accommodating pedestrians, bicycles, transit, freight and motor vehicles within a fine-grained urban circulation network where the allocation of right of way on individual thoroughfares is based on urban context, often determined through the process in this report;
2. Providing a compact and mixed-use environment of urban buildings, public spaces and landscapes that support walking directly through the built environment and indirectly by supporting human and economic activities associated with adjacent and surrounding land uses;
3. Achieving system-wide transportation capacity by using a high level of multimodal network connectivity, serving walkable communities with appropriately spaced and properly sized pedestrian, bicycle, transit and vehicular components rather than by increasing the vehicular capacity of individual thoroughfares; and
4. Creating a supportive relationship between thoroughfare and context by designing thoroughfares that will change as the surroundings vary in urban character.
Walkable communities have the following characteristics:
1. A mix of land uses in close proximity to one another;
2. A mix of density including relatively compact developments (both residential and commercial);
3. Building entries that front directly onto the sidewalk without parking between entries and the public right of way;
4. Building, landscape and thoroughfare design that is pedestrian-scale—in other words, that provides architectural and urban design features scaled and detailed to be appreciated by persons who are traveling slowly and observing from the sidewalk at street level;
5. Thoroughfares designed to serve the activities generated by the adjacent context in terms of the mobility, safety, access and place-making functions of the public right of way; and
6. A highly connected, multimodal circulation network, usually with a fine "grain" created by relatively small blocks providing safe, continuous and balanced multimodal facilities that capitalize on compact urban development patterns and densities.
The above principles and characteristics are the qualities found in urban places where development pattern, intensity and design combine to facilitate frequent walking and transit use. In these places, the nonauto modes are attractive and efficient choices for many people, in concert with automobiles and their convenient and accessible parking. An increasing number of communities are recognizing the value of these features and are embracing them in land use, urban design and transportation plans, often using techniques drawn from planning and design movements such as smart growth and new urbanism.
Continuum of Walkability
At some level nearly every place in the built environment is walkable. Some places, such as freeways or highways do not allow for pedestrians. At the other extreme, public spaces such as plazas, parks and pedestrian malls are primarily for pedestrians and generally exclude vehicles. Thoroughfares that are in between these two extremes require trade-offs between pedestrian and vehicle priority. The focus of this report is on the thoroughfares that are "pedestrian supportive" as shown in the spectrum of pedestrian and vehicle sup-portiveness below. Some of the concepts in this report can be used in pedestrian-tolerant areas as well.
(Extended text description: Sidebar image - A graphical illustration that depicts the Focus of Report showing the relationship between Pedestrian Priority and Vehicle Priority. Two columns indicating Pedestrian Status versus Vehicle Status and a gradation between pedestrian places being vehicle intolerant through vehicle places that are pedestrian intolerant. The Pedestrian Status column has the following items, from top to bottom: Pedestrian Places, Pedestrian Supportive, Pedestrian Tolerant and Pedestrian Intolerant. The Vehicle Status column has the following items, from top to bottom: Vehicle Intolerant, Vehicle Tolerant, Vehicle Supportive and Vehicle Places. In between the two columns, there are arrows which point back and forth between text items. Pedestrian Places points to Vehicle Intolerant, Pedestrian Supportive and Pedestrian Tolerant both point to Vehicle Tolerant and Vehicle Supportive, and Pedestrian Intolerant points to Vehicle Places.)
Pedestrian priority on urban thoroughfares falls into the following ranges:
Thoroughfares that are pedestrian supportive range from being tolerant to supportive of vehicular access and mobility. The specifics of the community's objectives, transportation needs and priorities are resolved through the CSS process to arrive at the proper thoroughfare design solutions.
Source: Adapted from a system for describing "degrees of walkability" for street environments, Charlier Associates.
As the successful design of walkable communities is complex and is not the primary focus of this report, the following references are provided as some of the many sources for useful guidance regarding the overall design of walkable communities:
1. Promoting Sustainable Transportation Through Site Design: An ITE Recommended Practice, 2010. This document provides specific guidance regarding the design of sites to create a context that supports walkable urban thoroughfares.
2. SmartCode v9.2, (Andres Duany, Sandy Sor-lien, and William Wright, 2008). This document is a model development code for walk-able communities that is based upon the Transect.
Applicability of this Recommended Practice
This recommended practice provides guidance for designing urban thoroughfares—facilities designated as arterials or collectors—to support walkable communities. Most applications of the design guidance included in this report will often apply in one of the following two circumstances:
1. A thoroughfare project in an existing walkable community where its multimodal character is to be preserved and enhanced; or
2. A thoroughfare project in an area where community goals call for a walkable context, in which case applying this design guidance will shape public investment to advance those goals.
Both circumstances can apply to either new construction or retrofit projects.
Commitment to walkable communities as a goal means that throughout the design process, location will serve as a design control (see Chapter 7). As a result, design decisions will consistently favor those elements and dimensions that are most supportive of walkable community characteristics. Examples of the design-decision processes favoring walkable community outcomes are provided in Chapter 5.
Other development contexts will also benefit from applying the guidance presented in this report. These include places characterized by business parks, residential subdivisions and strip commercial development. In areas such as these, outside of existing and evolving walkable communities, this report can help designers provide benefits including
In cases where the design guidance is being used in development contexts other than walkable communities (existing or planned), design controls other than location may dominate trade-off decisions.
Relationship to Other Guidance
This report supplements and expands on policies, guides and standards commonly used by state and local transportation, engineering and public works engineers and planners. Those publications include A Policy on Geometric Design of Highways and Streets (AASHTO 2004a); Guide for the Planning, Design and Operation of Pedestrian Facilities (AASHTO 2004b); Guide for the Development of Bicycle Facilities (AASHTO 1999); Highway Safety Design and Operations Guide (AASHTO 1997); Roadside Design Guide (AASHTO 2002); as well as state department of transportation design policies and manuals, local municipal street design standards, urban design guides and guidances published by other standard-setting organizations. This publication expands on information published by the Federal Highway Administration (FHWA) in Flexibility in Highway Design (1997) and the Manual on Uniform Traffic Control Devices (2009) and builds upon the considerations in developing context sensitive solutions described in A Guide for Achieving Flexibility in Highway Design (AASHTO 2004c). This report is intended to illustrate how AASHTO guidance can be applied to roadway improvement projects to make them more compatible with community objectives and context in urban areas.
The flexibility encouraged in this report is consistent with the policies and intent expressed in the American Association of State Highway and Transportation Officials' (AASHTO) Policy on Geometric Design of Highways and Streets. Most of the criteria in this report are based on AASHTO design criteria, and this report shows how the criteria can be applied to create context sensitive designs in places with the qualities of traditional urbanism. This report presents guidance from sources other than AASHTO, citing these sources at the end of each chapter. This report incorporates by reference consistency with guidelines and standards published in the latest version of the Americans with Disabilities Act Accessibility Guidelines (ADAAG) as well as the Public Rights-of-Way Accessibility Guidelines (PROWAG), which both can be found at www.access-board.gov.
This report augments information found in the above resources by providing guidance on
1. Applying CSS principles in the planning and design of urban thoroughfares;
2. Considering a broader set of factors during the planning and design of walkable urban thoroughfares;
3. Recognizing the importance of context, the role of sites and buildings and how context influences the design of the thoroughfare and vice versa; and
4. Providing an understanding of how thoroughfare design criteria should vary depending on the context through which the thoroughfare passes.
This report is divided into three parts: introduction, planning and design. There are ten chapters:
Table 1.1 lists the chapters and provides an overview of the material that is addressed in each chapter.
Chapter 6 provides general design parameters and example designs for urban thoroughfares with speeds up to 35 mph in areas with high levels of pedestrian, bicycle and transit activity. Chapter 7 presents general design controls that apply to urban thoroughfare design. Design guidelines in Chapters 8 through 10 focus on the streetside, traveled way and intersection design of lower-speed thoroughfares, but much of this guidance also can be applied to higher-speed facilities.
Who Should Use This Report
This report is for practitioners and stakeholders involved in planning and designing urban thoroughfares for walkable communities. Users are encouraged to consider the principles and guidelines in this report in conjunction with applicable local policies and manuals. table 1.2 presents many of the intended users and their responsibilities where CSS principles may be considered. Each user listed in table 1.2 represents a different set of stakeholders that bring different perspectives and responsibilities to the transportation planning and project development processes to best meet the needs of all the stakeholders. However, all users may benefit from an understanding of CSS principles and how they might be integrated into their work.
Table 1.1 Contents of This Report
|Chapter Title||Material that is Addressed|
|Part 1: Introduction|
|1—Foundation||The background behind this guidance and an overview of the principles of CSS.|
|Part 2: Planning|
|2—Planning and Developing Context Sensitive Urban Thoroughfares||An overview of the transportation planning and project development process and how CSS principles are applied with these processes.|
|3—Network and Corridor Planning||An overview of thoroughfare network types, characteristics of successful networks and network design guidelines. An overview of the corridor planning process and the role of CSS.|
|4—A Framework for Walkable Urban Thoroughfare Design||An introduction into the design framework for context sensitive thoroughfare design, context zones, their characteristics and the features that create context and a description of thoroughfare types and their relationship with functional classifications, compatibility with context zones and general design parameters.|
|Part 3: Design|
|5—Thoroughfare Design Process||A process for using this report to design thoroughfares, how to design thoroughfares within constrained rights of way and flexibility in the application of design criteria.|
|6—Thoroughfare Designs for Walkable Urban Areas||General design parameters for thoroughfare types, variations in the street-side and traveled way under varying conditions and example thoroughfare designs.|
|7—Design Controls||A discussion of the engineering controls and level of flexibility critical in context sensitive design, including design vehicle, roadway geometrics and design speed.|
|8—Streetside Design Guidelines||General principles, design considerations and detailed guidance for the design of the elements that comprise the streetside.|
|9—Traveled Way Design Guidelines||General principles, design considerations and detailed guidance for the design of the elements that comprise the traveled way.|
|10—Intersection Design Guidelines||General principles, design considerations and detailed guidance for the design of the elements that comprise multimodal intersections.|
Table 1.2 Intended Users and Responsibilities
|Land Use Planner||
- Urban Designer
- Landscape Architect
- Elected Officials
- Appointed Commissioners
- Local, Regional and State Agencies
American Association of State Highway and Transportation Officials. 1997. Highway Safety Design and Operations Guide. Washington, DC: AASHTO.
American Association of State Highway and Transportation Officials. 1999. Guide for the Development of Bicycle Facilities. Washington, DC: AASHTO.
American Association of State Highways and Transportation Officials. 2002. Roadside Design Guide. Washington, DC: AASHTO.
American Association of State Highway and Transportation Officials. 2004a. Policy on Geometric Design of Streets and Highways, Fifth Edition. Washington, DC: AASHTO.
American Association of State Highway and Transportation Officials. 2004b. Guide for the Planning, Design and Operation of Pedestrian Facilities. Washington, DC: AASHTO.
American Association of State Highways and Transportation Officials. 2004c. A Guide for Achieving Flexibility in Highway Design. Washington, DC: AASHTO.
Federal Highway Administration and Atlanta Regional Commission. Accessible via www.fhwa.dot.gov/context/index.cfm.
Federal Highway Administration. 1997. Flexibility in Highway Design. Washington, DC: FHWA.
Federal Highway Administration. 2009. Manual on Uniform Traffic Control Devices. Washington, DC: FHWA.
Federal Highway Administration. 2005. Executive Order 13274—Purpose and Need Work Group Baseline Report, March 15. Washington, DC: FHWA.
Institute of Transportation Engineers. 2010. Promoting Sustainable Transportation Through Site Design: An ITE Recommended Practice. Washington, DC: ITE.
Transportation Research Board. 2002. NCHRP Report 480: A Guide to Best Practices for Achieving Context Sensitive Solutions. Washington, DC: TRB.
Transportation Research Board. 2004. "Context Sensitive Design Around the Country, Some Examples." Transportation Research Circular Number E-CO67—July. Washington, DC: TRB.
U.S. Architectural and Transportation Barriers Compliance Board. 1999. Accessible Rights-of-Way: A Design Guide.
Sources of Additional Information
Transportation Research Board. 2004. NCHRP 69: Performance Measures for Context Sensitive Solutions-A Guidebook for State DOTs. [NCHRP Web-Only Document 69 (Project 20-24(30)).] Washington, DC: TRB.