California Senate Bill 743 requires the state to develop new transportation impact evaluation methods. Specifically, it requires the Governor’s Office of Planning and Research (OPR) to establish alternatives to roadway level-of-service (LOS) for evaluating developments in transit-oriented areas, but its impacts will probably be much broader.
Most practitioners dislike political interference such as this, but to be honest, transportation engineers and planners brought it on themselves. Local and state agencies continue to use roadway LOS as a primary transport impact indicator, although it fails to reflect community needs: it assumes that “transportation” consists only of automobile travel and it discourages infill development, and so is an obstacle to creating more accessible and multi-modal communities. For years experts have recommended replacing roadway LOS with more comprehensive indicators, but little has changed. This legislation forces the profession to develop Twenty-First Century evaluation methods.
I hope practitioners will embrace opportunities such as this. They can help establish strategic goals for developing, optimizing and implementing better evaluation methods, including a research agenda, data collection requirements, professional development programs, and inter-organization partnerships. This demonstrates leadership and insures that change will reflect our knowledge of the planning process. It is also a terrific opportunity for professional development: the first planners and engineers to learn these methods will have job security because they can provide the solutions that meet community needs.
Not everybody agrees. The Western District of the Institute of Transportation Engineers (ITE) drafted a letter which defends use of roadway LOS and highlights obstacles to change. Chatter on the ITE Members Forum has also been largely negative, although only a few members have commented.
The OPR is accepting comments on this policy until this Friday, 14 February. I am submitted a document titled, Beyond Roadway Level-of-Service: Improving Transport System Impact Evaluation. Here are its key conclusions and recommendations:
Transportation planning decisions have many direct and indirect impacts so it is important to use comprehensive and multi-modal analysis when evaluating policies and projects. Current practices, which rely primarily on congestion intensity indicators, such as roadway level-of-service (LOS), overlook important accessibility factors and impacts. Many experts recommend replacing roadway LOS with more comprehensive and multi-modal indicators, particularly when evaluating urban infill developments that may increase local congestion but improve overall accessibility.
Roadway LOS is particularly inappropriate for environmental impact analysis. People often assume that traffic congestion increases fuel consumption and pollution emissions, but per mile fuel consumption and emission rates are minimized at 40-50 miles-per-hour, so moderate congestion (LOS C or D) tends to reduce fuel consumption and emissions compared with freeflow speeds, and roadway expansions often increase per capita fuel consumption and emissions by inducing additional vehicle travel.
Models are available for predicting how a particular policy or project will affect vehicle trips, travel and fuel consumption, which are useful indicators since reduced trips/travel/fuel consumption generally indicate lower traffic and environmental impacts. Like all models, they have various degrees of uncertainty, but can be improved with targeted research and data collection programs. In recent years, transportation professional organizations have developed multi-modal level-of-service and quality-of-service evaluation models. These can be useful in some situations, but they do not account for connectivity or proximity and so do not indicate overall accessibility.
Of currently available methods, the most comprehensive and multi-modal is multi-modal accessibility modelling which measures the time and other costs to reach services and activities by various modes, taking into account travel speed, network connectivity and geographic proximity. These range from relatively simple indicators such as WalkScore and TransitScore, to sophisticated integrated models that account for numerous accessibility factors. More work is needed to improve and standardize these methods so they can be used to evaluate specific projects, but they could be operational within a few years.
Critics argue that these alternative evaluation methods are difficult and costly to implement, and their results are unreliable. This only seems true because roadway LOS methods and information resources have had decades of development, so they seem convenient and affordable, and their results are not particularly accurate. Alternative evaluation methods are developing rapidly, and with targeted research and data collection, supported by state agencies and professional organizations, could be operational within a few years.
To its credit, the California Department of Transportation took a bold step recently by inviting the State Smart Transportation Initiative to perform an assessment of the agency’s performance. The results, published in the just-released report, The California Department of Transportation: SSTI Assessment and Recommendations, is an amazingly honest and insightful review of the organization’s structural problems, and recommendations for improvement. This type of critical assessment is a priceless gift to practitioners ready to embrace change.
What do you think? How can our profession better accommodate appropriate change? What are you doing to help this occur?
J. Richard Atkins and Daniel S. Turner (2006), “Upgrade Stakeholder Service by Changing your Agency’s Organizational Culture,”ITE Journal, vo. 76, No. 12, December, pp. 30-37.
GIZ (2011), Changing Course in Urban Transport- An Illustrated Guide, Sustainable Urban Transport Project.
Thomas Kuhn (1970),The Structure of Scientific Revolutions, University of Chicago.
Todd Litman (1999), “Reinventing Transportation: Exploring the Paradigm Shift Needed to Reconcile Transportation and Sustainability Objectives,”Transportation Research Record 1670, Transportation Research Board, pp. 8-12.
Steve Lockwood (2005), “Systems Management and Operations: A Culture Shock,” ITE Journal, Vol. 75, No. 5 (www.ite.org), May 2005, pp. 43-47.
Quality Information Center by the American Association of State Highway and Transportation Officials, provides information about quality management programs used by public and private transportation organizations.
TransManagement (2005), From Handshake to Compact: Guidance to Foster Collaborative, Multimodal Decision Making, TCRP Report 106 and NCHRP Report 536, Transportation Research Board.
TRB (2001), Managing Change in State Departments of Transportation, National Cooperative Highway Research Program, NCHRP 20-24(14), Transportation Research Board (www.trb.org).