Sunday, November 1, 2015

Using Transportation Performance Measures to Shape Your City

Posts have become quite infrequent here, but with good reason.  I began an internship in the planning field three months before graduating from the University of Washington with my Master of Sustainable Transportation degree.  As such, I've relocated to Washington, DC and was recently promoted to a full-time position.  The following is some placemaking perspective I've gained while researching performance measures for local streets and roads.

As I've begun to attend professional conferences in the past year and a half (CNU22 in Buffalo, the CNU Transportation Summit in New York, and CanU7 in Ottawa), I've noticed many long-time members remarking on the vastly increased focus on transportation topics.  The self-evident link between transportation and land use - How does one design a neighborhood without considering how its inhabitants will move within it or between neighborhoods? - is being properly recognized, and with it the compartmentalization of disciplines continues to diminish.  The following paragraphs serve as an overview of how one might construct a performance measure set for the basic corridor unit, the local street, which reinforces spatial and placemaking goals.

Development of the New

While the concept of a performance measure is certainly nothing new, packaging of measures and a focus on sustainability achieved prominence from 1994 to 2006 through the evolution of the LEED program at the building level.  Since then similar project-based scoring and certification systems have been developed on the transportation side, most notably Greenroads.

Greenroads is a sustainability rating system for roadway design and construction.  It can be applied to a variety of transportation projects including new roads and the reconstruction of and/or rehabilitation of old roads and bridges.  A collection of sustainability best practices, called “credits,” aggregate into a final project score which indicates overall sustainability of the roadway.  The goal of the system is to create an inclusive single metric for considering overall roadway sustainability that is quantitative and enables informed design and construction decisions.

While the system criteria normally combine to form an overall project score, the individual measures found in the Greenroads Scorecard can be disaggregated and applied to goals stated in municipal vision plans.  For example, aspects of roadway design and implementation such as runoff control and habitat conservation can relate to environmental goals.  The table below contains additional pertinent examples.

Measure Sub-Measure Use Justification
Environment & Water Rating Habitat Conservation Shows a commitment on the part of the local government to environmental sensitivity and establishes sustainability as a transportation network priority.
Vegetation Quality
Soil Management
Runoff Flow Control
On-site Water Treatment
Materials & Design Rating Recycled Content Clients have cited implementation cost savings associated with decreased life-cycle costs of both raw material and design for durability.
Local Material Content
Long-life Design
Access & Livability Rating Multimodal Connectivity Adds more dimension to street design. Aggregates factors affecting all people that cannot be isolated from transit or vehicle counts.
Active Transportation Inclusion
Noise Reduction

Evolution of the Classics

Classic performance measures are evolving as well to capture the impact of Complete Streets or similar initiatives.  Take the example of the Transportation Master Plan for the City of Ottawa.  Quite possibly my favorite transportation plan, and one that I've cited in both academic and professional work, the Ottawa TMP dedicates an entire chapter to the provision of safe and efficient roads.  In addition to the adoption of a complete streets policy and an updating of design standards, the plan uses multimodal level of service (MMLOS) indicators a means to assess road design and allocate right of way with a broader goal of moving people.  This represents a fundamental shift in focus in a discipline still known today as traffic engineering.  Metrics that have guided road design decisions for decades have focused only on moving vehicles through the roadway network as quickly and efficiently as possible.  MMLOS broadens the focus to all modes, to understand how design choices impact the journey quality of each user – pedestrian, cyclist, transit rider, motorist, or truck driver.

As with the Greenroads ratings, MMLOS measures can be considered umbrella metrics, pieced together from simpler sub-measures.  Adding to the old standbys of motor vehicle delay and capacity ratios, pedestrian delay, cyclist travel stress, and transit travel time ratios are now taken into account.  These measures prove their usefulness in shaping the urban form during review processes as development applicants are required to submit transportation impact assessments and provide funding for mitigation.

Packaging Priority

There are other groups of metrics pertaining to local streets and roads.  Roadway safety comes to mind, using collision and citation data to identify trouble areas and prioritize safety initiatives.  There are no doubt many others.  When choosing performance measures to bundle into a comprehensive set, some priority identification is necessary.  This is made easier by clearly defined goals stated upfront in jurisdictional transportation plans.  It should be simple to attach a performance measure proposed for inclusion to one or more expressed objectives.

Further Applicability

Beyond consistency with the aims of a given transportation plan, performance measures occupy a place at the heart of what many consider to be the future of transportation financing; local option taxes.  Regardless of the form of the taxation (sales, fuel, property, etc.), taxes approved by voters via referendum for a specific use generally come with strict strings attached.  For example, in Alameda County, California, Measure B, a half-cent transportation sales tax, was approved by voters in 2000 (subsequently renewed and increased via Measure BB in 2014) to serve major countywide transportation needs.  Beyond project regulations, applying agencies must meet specific criteria including the adoption of a Complete Streets policy.  Taking this accountability a step further, annual compliance reports must be prepared by all recipient agencies.  Noting that local option funding could be the topic of a lengthy article in and of itself, it seems rather obvious that appropriate performance measure bundles are a critical tool for proponents of such legislation not only to realize an initial implementation, but to ensure the future of such a program through retention of the public trust.


In the past few months I have come to a much greater appreciation of transportation performance measures for local streets and roads.  The sheer number of them and the flexibility of their application has increased to a level where their use can be more advantageous than onerous, especially when seeking funding sources.  Finally, the new generation of measures intuitively connect to the overarching goal of the sustainable planning profession, enriching the places we live while providing for their future.

1 comment:

heckeranddecker said...

Great post - enjoy hearing again how the mmlos shifts the way we think about STREETS.

Good to have your voice back here. Looking forward to your next observations.