While it’s generally accepted that dense, mixed-use development promotes active travel, researchers don’t have a consensus on exactly how, and to what degree, land use determines people’s travel patterns.

NITC’s latest report, Active Travel Behavior and Spatial-Temporal Land Use Mixing, provides some clarity on the topic.

NITC fellow Steven Gehrke focused his dissertation research on transportation-land use interaction, and sees land use mix as a multidimensional construct.

“We can refocus—away from increasing density—and think more about how we configure land uses,” Gehrke said.

According to Gehrke’s research, more density does not necessarily equal more walking. Rather, the complementarity, composition, and configuration of land use types is essential for cultivating walkability.

Gehrke, who graduates this spring with a Ph.D. in civil and environmental engineering from Portland State University, conducted three empirical studies under his dissertation grant. The first focused on improving measurements of land use mix, introducing a land use mix measurement of the composition and configuration of local land use types.

The second study looked at other smart growth principles, like employment concentration and pedestrian-oriented design.

"All of these are potential determinants of why we decide to walk. Living in a smart growth neighborhood strongly predicts your likelihood to walk,” Gehrke said.

The third study was concerned with the geographic scale at which we measure the built environment.

“A one-mile buffer doesn’t work for every study. Mix is very important at a small scale, and density could be more important at a larger scale,” Gehrke said.

By deconstructing land use mix and reimagining this multifaceted construct as a collection of complementary landscape pattern metrics, Gehrke’s work provides important theoretical and empirical contributions for transportation-land use planning research and practice.

Gehrke will give a webinar on this research Tuesday, July 25.

He presented the research at the 2016 annual meeting of the Transportation Research Board, and gave a recap at a PSU Friday Seminar along with NITC dissertation fellow Kristina Currans. For more details, visit the project page or watch a recording of the January 2016 seminar.