Development principles that support transit can be successfully adapted to suburban settings, and doing so improves land-use mixes and walkability. That and other findings are discussed in Urban Design, Transportation, Environment and Urban Growth: Transit-Supportive Urban Design Impacts on Suburban Land Use and Transportation Planning. The recently published report, by Carol Swenson, formerly of the Design Center for American Urban Landscape at the University of Minnesota, and Frederick Dock of Meyer, Mohaddes Associates, Inc., is eleventh in a series of the Transportation and Regional Growth Study.
Many metropolitan areas, including the Twin Cities, are exploring transit-supportive development as a strategy for balancing growth and sustainability. However, region-wide implementation of transit-supportive principles will require coordination of land use decision-making at the local level with transportation infrastructure planning and transit service decision-making at the county and regional levels. In order to support that coordination, the regional transportation model must be enhanced to allow for estimating travel behavior at both neighborhood and subregional scales, say the report’s authors. This report summarizes their work on enhancements to measure both the individual and accumulative impacts of transit-supportive urban design strategies.
The report consists of three sections. The first documents the researchers’ urban design analysis of four transit-supportive development proposals. Two scales of sites were studied: those that were moderate in both land area and development intensity, and those that were either large in land area or planned to be intensively developed. Transit-supportive principles of mixed use, organization, and connectivity were used to measure and enhance current proposals for each site. Enhancements included modifying block size, increasing the number of full intersections, relocating mixed-use areas closer to probable transit routes, and modifying single land uses. Results of this phase of the study showed that transit-supportive development could work comfortably in existing suburban conditions and within different scales and types of suburban sites.
The second section of the report discusses the researchers’ development of model enhancements in the form of a subarea model. These enhancements were designed to allow better evaluation of transit-supportive urban design and to address the relationships between land-use density and type, vehicle trip-reduction and transit usage, shorter-distance tripmaking, pedestrian activity, and proximity to transit. The researchers found that the subarea transportation model proved sensitive enough to detect changes in tripmaking patterns at both the site and subregional scales. Two types of tripmaking contributed to these changes: short-distance trips between transit-supportive developments and walking or bicycle trips within developments.
The last section of the report uses the subarea model developed by the authors to analyze a subregional transit-supportive growth scenario, results of which clearly demonstrate the benefits of transit-supportive development strategies, the authors say. For example, transit-supportive developments were shown to positively affect the jobs/housing balance in the subregion. If the entire region were modeled, the authors would expect to see even more benefits. Other conclusions drawn by Swenson and Dock are that transit-supportive development requires interjurisdictional planning and shows its greatest potential when it is planned and implemented in the aggregate. Additionally, to realize the benefits of transit-supportive development, suburban communities need to plan cooperatively for it.