Whole Network Prioritization: Enabling Resilient Frameworks for Future Investments
By: Erin David, AICP, Alta
Master plans establish the vision for a community’s transportation system. Often, this reflects an ideal network that emphasizes complete and connected low-tress travel options. Yet, with limited resources, we understand that achieving this vision will take time and usually a little creativity. A successful plan will account for this and define a strategy for how to make meaningful, incremental change.
The foundation of this strategy is the prioritization framework. Prioritization is the tool that helps us understand which projects are expected to have the greatest impact and identify where to start. Ultimately, it is a mechanism for translating a plan’s vision and goals into a tool that guides project implementation.
The most effective prioritization strategies rely on data that is readily available, use measures that are easily replicable, and connect directly to the objectives of the plan. More specifically, it provides an opportunity to directly reflect community values in plan implementation. The limitation to this approach, however, is that most often, we evaluate only the performance of specific projects identified in the plan, including what infrastructure it includes, where it starts, and where it ends.
Yet, we also know that:
- Physical conditions change over time, resulting in new approaches to project design.
- Funding availability may not support implementation of the full extent of the project.
- Opportunities arise to coordinate with other projects and development, or
- Projects will ultimately address multiple modes of travel, reflecting different priorities and needs in the network.
- Although community values may remain the same, how to best achieve them will likely shift over time.
Ultimately, considering only proposed projects can limit our ability to remain flexible, approach transportation planning as a comprehensive system, and adapt to rapidly changing conditions in our cities and wider regions.
What are our options?
As an alternative to evaluating projects only, we can instead consider the underlying need across the entire network — regardless of where projects are located. This approach, known as Whole Network Prioritization, considers both deficiencies and opportunities of the full transportation network based on data captured during the needs analysis of a project, regardless of the complexity or intensity of a proposed solution. This allows us to look at sections of the network and understand which blocks, corridors, or larger areas have the greatest potential to positively impact the transportation system.
Further, when built on a plan’s guiding principles, we have an opportunity to consider the unique aspects of different travel modes, evaluate the network based on different measures of safety and comfort, and even advance priorities identified in other plans — such as ADA transition plans or regional transportation systems. The guiding principles — or community values — help us understand and evaluate how to best transform the network.
Prioritization that considers the underlying need across the full transportation network, rather than evaluating only specific projects identified in master plan recommendations, can lead to resilient frameworks that generate greater positive impacts for people using the transportation system.
A Multi-Modal Case Study: Move Tucson
The City of Tucson recently tested this approach as part of Move Tucson, the city’s comprehensive mobility master plan. Move Tucson identifies a vision for the city’s mobility future and considers the needs of all modes of travel — from greenways and sidewalks to projects addressing traffic congestion and signal technology. It builds on the success of recent local and regional plans that focus on specific modes and instead looks at how Tucson can approach the transportation system holistically to create a balanced system with expanded choices for travel. With this in mind, the plan focuses first on the system vision without specific fiscal constraints.
The result is more than 230 projects and over $5.7 billion of possible improvements. While some projects may focus on a single mode — such as sidewalk improvements, greenways, or high-capacity transit routes — many projects address the needs of all modes, including new sidewalks, improved bikeways, upgraded traffic signals, and more. It is a bold vision that will require not only significant investment to achieve, but also innovative and flexible approaches to implementation.
Such a broad range of improvements also requires a unique approach to prioritization to understand which projects can have the greatest impact. Move Tucson presents two specific challenges in evaluating priority projects:
- Prioritization must account for the different needs and benefits of each mode. Specifically, any preference for mode must be driven by the plan’s guiding principles and not be tied to the inherent qualities of a given project, such as physical length of improvement.
- Prioritization must be repeatable and flexible. To respond to funding opportunities, the city must be able to evaluate the needs of a project with different start and end points than what is identified in the plan.
Ultimately, the selected prioritization framework needed to consider projects that benefit multiple modes of travel, fairly evaluate projects of varying lengths, and provide flexibility for various funding scenarios.
The resulting process builds on the plan’s six Guiding Principles and uses a multi-step approach to understand network needs, score projects, and refine the results based on project performance. The six steps are outlined in the following graphic.
This process measures all network segments in the city, regardless of project location, based on results of the Network Needs Analysis. The underlying scores are then summarized to the unique projects identified in Move Tucson, accounting for project length. The calibration phase then provides an opportunity to assess the unique benefits of each project and its role in achieving plan goals. For example, scores were increased for projects that received public support, provided opportunities for shade and cooling in areas with high heat severity, or projects that had a high cost-benefit ratio.
This results in a dynamic approach to prioritization that the City can reassess over time utilizing the underlying network scores. This creates opportunities to account for shifting project extents, changing network conditions, shifting funding opportunities, and more.
To learn more about Move Tucson, check out the Move Tucson website. In the meantime, get monthly updates of the latest Alta news here.
