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July 2009
Access to Destinations researchers highlight policy implications at annual research conference
Kevin Krizek
David Levinson
“Why are we here?” is more than just an existential question for David Levinson and Kevin Krizek, two researchers whose work probes the complex interconnections between transportation and land use.
Addressing the opening plenary session of the 20th Annual CTS Transportation Research Conference, Levinson pointed out that the audience of researchers, policymakers, and others had braved the morning rush hour in order to come together in a kind of “temporary city” because the conference offered access to a broad spectrum of transportation professionals. The concept of accessibility, he said, is key to understanding travel behavior and location decisions.
Levinson, the Richard P. Braun/CTS Chair in Transportation Studies and director of the Nexus transportation research group at the University of Minnesota, serves as co-leader of the Access to Destinations Study. For the past four years, the study’s multidisciplinary research team has investigated the evolution of transportation networks and land use patterns across the Twin Cities region. CTS provides coordination and support for the study.
Studies of transportation networks have traditionally focused on mobility—essentially, measuring travel speeds. But Access to Destinations argues for a different and more nuanced view of transportation—one that takes into account the destinations that travelers can reach in order to meet their daily needs.
“The issue is what you can reach, not how fast you can go,” Levinson said. “Speed is a means, not an end.”
From the perspective of access, Levinson
said, the fact that roads are crowded with travelers trying to reach a wide range of destinations can be seen as an indicator of economic success.
“All of the great cities have congestion,” he noted, but congestion can best be understood as an indicator of economic success; the fact that roads are crowded with people going about their daily business shows that the city is providing what they need. Stagnant economies, by contrast, are largely free of congestion because there is little reason to travel.
Creating access, Levinson explained, induces people to travel and participate in the economy. This activity leads to higher land values, which encourage developers to build housing and commercial properties, creating new destinations and higher levels of accessibility. As the cycle continues, greater numbers of travelers using the transport infrastructure are likely to produce congestion and increase the cost of travel—but revenue systems based on the amount of travel (such as gas taxes or road user fees) can take advantage of this situation to fund new infrastructure.
David Levinson, Kevin Krizek, Curt Johnson, Mariia Zimmerman, Tim Henkel
Capturing value and using it to build new infrastructure that improves access is critical, Levinson said—if this is not done, the entire system begins to break down. Cities exist as long as they provide access to the things people care about. If people cannot access jobs, shops, and amenities—or if their preferences change over time—history shows that cities can stagnate or even disappear entirely.
In a modern context, quantifying changes in access over time requires integrating many complex data sets, including the geography of roads and public transportation systems, records of land development and housing sales, employment statistics, and travel time estimates for thousands of origins and destinations via a variety of transport modes.
Over the last four years, the research team, drawn from diverse disciplines including public policy, engineering, economics, and urban planning, has completed several related research tasks. Initial results are now taking shape. The ultimate goal, Levinson said, is a set of accessibility maps and models that will show changes in the context of land development and transportation network growth and help policymakers plan for the future.
All this attention to access begs the question of whether accessibility is increasing or decreasing in the Twin Cities region. The answer, according to Levinson, is “yes.” Urban growth has brought some areas greatly increased accessibility to destination types such as employment and shopping, while other areas have seemingly fallen behind, with their residents experiencing little improvement or even declining accessibility levels.
Findings like this have important policy implications for the region’s future. The question of whether the value of accessibility can be used to finance new infrastructure is currently the subject of a University of Minnesota study of value capture techniques. Another important issue is setting goals for the future of the region.
“We have a number of different alternative objectives, including equity and efficiency, and accessibility can play into all of them,” he concluded.
Highway congestion may get the most attention in the press, but non-automotive travel modes—walking, cycling, and public transit—are critical to the overall picture of regional accessibility. Study co-leader Kevin Krizek of the University of Colorado (formerly with the Humphrey Institute of Public Affairs) discussed the importance of these modes and the innovative techniques being used to analyze non-automotive travel.
Krizek highlighted changes in accessibility for cyclists and transit users in the suburban communities of Bloomington and St. Louis Park, as well as along the Hiawatha Corridor connecting Minneapolis to the southern suburbs; he also discussed pedestrian accessibility in the Macalester-Groveland neighborhood of St. Paul. He described the challenges faced by the research team, including determining realistic cycling speeds along different types of roads and estimating transit travel times based on bus schedules.
The most important contributions of the Access to Destinations Study, Krizek said, will be in helping to change perceptions about transportation planning and in creating new performance metrics that will help us understand the past and make informed choices about where we want to go in the future.