An Efficient Route to Applying Performance-Based Design Guidance

 

Traditionally, transportation engineers have been trained to apply a set of standards that primarily address function in road design. The problem with these standards is they do not always fit within the unique context of each project, and this can result in undesirable, sometimes uncomfortable conditions for the people who use that transportation system.

Performance-based design is a shift away from applying strict design standards and toward designing based on context. Performance-based design brings many benefits to projects.

#1: It means built projects will better meet the needs of users. Projects can reflect the original intended community outcomes where people want to live, work, and play.

#2: It gives people a meaningful connection to transportation infrastructure. By establishing urban context categories that serve their needs, rather than just building a highway based on coded standards that may not fit the context, transportation infrastructure elements become valued community assets.

#3: It frees engineers to be engineers again. Performance-based design calls on engineers to design based on fundamental engineering principles, context, and need, rather than only following fixed standards.

For these reasons and more, several state departments of transportation have been moving away from rigid standards and toward performance-based design. However, in most cases, the journey toward performance-based design has been frustratingly slow, requiring potentially millions of dollars in design manual updates.

In December 2019, the Oregon Department of Transportation (ODOT) released a document that addresses the need more efficiently.

Blueprint for Urban Design, ODOT’s Approach for Design in Oregon Communities

As noted, updating all design manuals to performance-based standards can be a slow and expensive process. So, rather than updating all manuals together in the near-term, ODOT released a bridging document that establishes the revised criteria to be used when designing urban projects on the state system. It’s called the Blueprint for Urban Design and it will enable ODOT to update their manuals in a more time- and cost-effective way over time, while beginning to incorporate current urban design criteria into ODOT designs now. Through the Blueprint, ODOT is making performance-based design its new approach to plan and design urban environments.

This means that we can use the new guidance to plan and design projects in urban settings in Oregon communities today, while also allowing agencies to spread out the investment of time and funds needed to update individual manuals.

“The Blueprint for Urban Design and its basis in Performance-Based, Practical Design is the next step in ODOT’s evolution of our urban design practices to include all transportation modes,” says Rich Crossler-Laird, Senior Urban Design Engineer at ODOT. “The journey started with Multi-Modal Stakeholder Involvement in the early 1990s and continued through Context Sensitive and Sustainable Solutions in the 2000s and then Practical Design in 2010. The Blueprint for Urban Design is the culmination of those earlier endeavors and, where appropriate, provides enhanced flexibility for inclusion of innovative urban design practices on ODOT projects.”

"The Blueprint for Urban Design is the culmination of those earlier endeavors and, where appropriate, provides enhanced flexibility for inclusion of innovative urban design practices on ODOT projects.”

- Rich Crossler-Laird, Oregon Department of Transportation

Building the Blueprint

The project began with an audit of ODOT’s urban design-related manuals. Kittelson, who served as the prime consultant on the project, summarized an audit of the manuals, highlighting potential benefits from additional urban design guidance and suggesting ways to integrate urban design guidance and principles.

To help shape identified issues, understand needs, and improve processes, we collected nearly 900 online survey responses and had discussions with 27 stakeholders in 4 small groups. The stakeholders expressed concerns related to flexibility, inconsistent communication and direction, inconsistent design exception process, successful collaboration examples, balancing priorities for all modes, clear definitions for facilities and context, and difficulties implementing innovative practices. We took this feedback to heart in the development of the Blueprint.

In the second phase of development, we developed topical memoranda to address crucial urban design challenges (bicycle facility selection, pedestrian crossings spacing, and target speed). These focused documents informed the content included in the Blueprint, which was published in December 2019.

Community Benefits

Thanks to the Blueprint, communities throughout Oregon will experience the benefits of context-sensitive transportation facilities that integrate sustainability into their communities.

The Blueprint emphasizes giving people choices about how they’ll get from point A to point B. For example, physically separating faster vehicles from vulnerable users, like bicyclists and pedestrians, has been shown to increase travel by bicyclist and people walking. Walking and bicycling become safe, comfortable ways to get around that are less expensive than driving (and parking) and improve health and wellness.

Roads and streets that align with neighboring land uses have shown economic benefit remodeling of current land uses, as well as redevelopment of parcels to serve the local communities. This creates a vibrant community where people want to live, work, and play.

When planners and engineers don’t consider their work through one another’s perspectives, the project suffers. This guidance gets them out of their silos, helping engineers think like planners and planners think like engineers.

Consistency With National Research

The Blueprint for Urban Design is consistent with national activities and associated publications, such as Federal Highway Administration performance-based practical design initiatives and the National Cooperative Highway Research Program (NCHRP) Report 785: Performance-Based Analysis of Geometric Design of Highways and Streets, which provides a framework for how to integrate design, operations, and safety by evaluating the overall performance of the project. Being the authors of NCHRP Report 785 informed Kittelson’s approach to developing ODOT’s Blueprint. NCHRP Report 855: An Expanded Functional Classification System for Highways and Streets is another related document, giving practitioners a starting point to adopt their own classification of contexts and defines the following land use contexts as rural, rural town, suburban, urban, and urban core.

What’s Next in Performance-Based Design?

ODOT’s innovative document is changing the way we plan and design projects in urban settings in Oregon communities. However, Oregon is not the only state where the land use context is becoming the driver of how we design our roads and streets. We hope that the bridging document model can be useful to other state departments of transportation looking to incorporate current performance-based design criteria into designs as quickly as possible, while making it manageable to update their foundational design manuals over time.

You can find the Blueprint on ODOT’s website. Don’t hesitate to reach out to either of us with any questions about this work. We are excited for the value it will bring agencies in Oregon, and we’d be happy to discuss it further!