The Transportation, Land Use and Housing Connection
Travel behavior and land use are interconnected. In academic research, travel itself is often treated as a demand derived from the activities for which it serves. In practice, coordinating and linking transportation and land use decision-making proves to be challenging.
In a series of NITC Research Roadmaps, we surveyed the state-of-knowledge and where we’re headed across six areas of transportation. Here we share the contributions of a decade of transportation and land use research from the National Institute for Transportation and Communities (NITC). Learn more here about the other impacts from a decade of research funded by the National Institute for Transportation and Communities.
Travel Behavior, Land Use Patterns, and External Impacts
NITC research has helped to unpack the influences of the built environment on travel behavior. A series of studies investigating trip generation rates found that the Institute of Transportation Engineering Trip Generation Handbook vastly overestimates vehicle demand, and developed alternative methods to estimate pedestrian trips in urban environments. Other NITC studies have improved our understanding of how transit-oriented development (TOD) can improve transit access, increase multimodal travel, and decrease transportation costs associated with vehicle ownership and use. Over time, TOD neighborhoods encourage residents to walk and take transit more while driving less.
We have improved our understanding about the travel behavior of people living and working in dense urban centers. A study of 70+ retail and service locations observed higher rates of multimodal travelers than previously expected by industry standards. Having this qualitative information has made it easier for practitioners to predict the outcomes of new developments, and to meet goals on reducing greenhouse gas emissions, decreasing automobile traffic congestion, and improving air quality and overall public health.
Transportation, Jobs/Housing, and Property Value
Economic vitality is a primary goal that practitioners consider when evaluating transportation and land use plans. A series of NITC studies explored the contribution of transit investments – particularly fixed-guideway transit systems – on real estate values, as well as employer and household location changes. Quality transit investments see higher rates of adjacent development within walking distance to the station, and often corresponding increases in land value. This indicates a vast latent demand for high-quality, TOD’s in U.S. metropolitan areas. This study also offers a robust data repository, publicly accessible, containing demographic data for workers and longitudinal employment data in relation to 52 transit systems in 35 metro areas across the country.
Other NITC work has focused on the relationship between bike accessibility and economic measures, such as business vitality and property values. Higher bike accessibility ratings were associated with higher residential – especially multifamily – property values, as well as office, retail, services, and park employment. Significant attention has been placed on how to consider the social equity impacts of bike infrastructure, including the impact of new plans on historically marginalized communities.
Attitudes, Preferences, Choices, and Decision-Making
Attitudes and preferences for characteristics of travel, households, and neighborhoods play a powerful, but less understood, role in understanding how different strategies and programs might increase access to destinations, lower transportation costs, and improve quality of life. NITC has contributed several studies that explore market response to programs and strategies targeting improved access to services. One study evaluated whether a pilot transportation demand management program in Portland, Oregon improved mobility by providing a suite of discounted transportation services to low-income participants. More than half of the participants tried new transportation modes they had not used before, including bike share, transit and ride-hailing.
Other NITC work recommends evaluating transportation options before residential (or workplace) location choices are made. One study evaluated residential location preferences and found a dissonance between stated preferences and location choices; in that residents often say they prefer more dense, urban neighborhoods than they actually do move to. This indicates a latent demand for more multimodal and accessible neighborhoods.
Housing and Transportation Affordability and Vulnerable Communities
Increases in land value are often a result of increased competition for limited supply, and rising rents and property values can displace vulnerable households. While transportation infrastructure investments may aim to improve multimodal access to opportunities, they could be adding pressures to the very communities they sought to help. NITC research offers strategies to address this, including the recommendation that the U.S. Department of Housing and Urban Development’s direct subsidies to more compact, walkable, and transit-oriented neighborhoods.
National-scale performance metrics are incredibly valuable, but not without limitations. Several NITC studies have demonstrated the value of locally driven data and analysis that can better identify neighborhoods' and households' needs. While multimodal investments can improve location efficiency and affordability, successful implementation requires localized analysis and meaningful public participation to achieve results that benefit all members of the community.
Our work has focused on vulnerable populations and the nuanced ways in which different people experience environments differently. These have included environmental justice populations within fast-growing suburban "boom towns;" refugee and immigrant communities in Texas and Arizona; people experiencing homelessless who access social services; and former inmates returning to society.
Integrated T&LU Planning and Evaluating Trade-Offs
Transportation and land use regulation and governance tend to be tied to different political jurisdictions, complicating the ability for local and regional practitioners to think about travel and land use in an integrated and complementary manner. NITC researchers have explored a variety of strategies to better synchronize transportation and land use planning. For example, rural towns and places with high natural amenity value are currently experiencing “big city problems” like rapid increases in population growth and tourism, low wages, lack of affordable housing, and income inequality. A series of NITC studies has focused on assessing challenges specific to these "Gateway and Natural Amenity Region Communities (GNAR)” to support stakeholders in effectively studying these areas to a degree that reflects their regional importance.
In order to move forward with more coordinated transportation and land use practice, it is essential that we identify, understand, and communicate the trade-offs on a wide range of goals and outcomes. The research summarized in this roadmap has taken steps toward achieving a variety of measurable outcomes that are sensitive to the implications for different populations, as well as producing evaluation and communication tools that can help facilitate discussions on these trade-offs as they correspond with both transportation and land use decisions.
What are the impacts and key findings of our research at the nexus of transportation, land use and housing, and the economic value of investing in multimodal infrastructure? Learn more about some impact stories below.
Decade of transportation and land use research has nationwide impact on the ITE Trip Generation Manual
and Dr. Kristina Currans have a long history of NITC-funded research collaboration on coordinating transportation and land development. To date, their research findings have had a transformative impact on the development of the data and methods used in transportation impact analysis (TIAs). Their work has been included in the latest edition of Institute of Transportation Engineers Trip Generation Manual (2020) and Handbook (2014), the industry standard referenced for trip generation data. They have advised the local governments of Portland, Bend, Clackamas County on their development review process and methods for assessing transportation system development charges. The State of California has considered their findings in the CEQA analysis related to climate change. This body of work has produced new knowledge and contributed to making the land development and transportation planning process more equitable, multimodal, and environmentally sustainable.
Despite having a receptive audience among transportation planners in public agencies in major U.S. cities, there are still barriers to widespread change from traditional development review processes that privilege the automobile to new approaches that place top priority on people. One of the pervasive challenges comes from community members’ lack of understanding of the complex issues involved in TIAs and the land development process, and fears of multifamily and infill housing and increased traffic congestion. The findings from their research and others need to be more widely communicated to the public in order to broaden understanding of the problem and policy solutions.
To that end, NITC has funded a technology transfer grant to create a series of comics to translate this research to storyform and convey difficult concepts. Learn more about Communicating Research through Comics: Transportation and Land Development led by Kelly Clifton of Portland State University and Kristi Currans of University of Arizona.
Evidence from 52 fixed-route transit systems found that proximity yields an increased share of jobs, increasing accessibility.
The researchers developed a "Employment-Worker Balance (EWB)" metric. A more accessible workplace translates to a more productive and resilient workforce. Low EWB scores near transit stations reveal low-hanging fruit for planners who wish to increase economic and housing resiliency.
Learn more about Transit Impacts on Jobs, People and Real Estate led by Arthur Chris Nelson of University of Utah.
A study of 12 census tracts in Cleveland, Ohio revealed that HUD’s Location Affordability Index (LAI) did not accurately reflect the needs of “shrinking cities”.
To better understand the real costs of housing and transportation in a declining urban context, NITC researchers conducted a household-level survey on those financial burdens and budget trade-offs across 12 Census-tracts in Cleveland, Ohio. The survey found that less than 9% of those households resemble any household type used by the LAI, and that the assumptions of the LAI tool did not hold true in “shrinking cities”–cities that have experienced significant population loss. The particular difficulty with the shrinking city context is that as urban sprawl continues unchecked, the rate of land consumption grossly outpaces the rate of population change. As jobs move out from the city center toward more suburban locations, there is very little population growth to support funding that would enable transit agencies to get people to those jobs. The report provides policy recommendations to help transit authorities overcome these transportation burdens, including ridesharing and van pools, bike share programs, and better bicycle and pedestrian infrastructure.
"Dr. Ganning’s thorough and convincing analysis of the strengths and weaknesses of the Location Affordability Index led HUD to rethink using Census block groups as the geographical unit of analysis. As a result, Version 3 of the Location Affordability Index (published in April 2019) was generated at the Census tract level, addressing multiple data and methodological problems identified by Dr. Ganning in her 2017 article."
Josh Geyer, Office of Environment and Energy, High-Performance Buildings Team, U.S. Department of Housing and Urban Development
Learn more about the project What do we know about Location Affordability in U.S. Shrinking Cities? led by Joanna Ganning, Cleveland State University
People who bike to bars, restaurants, and convenience stores spend the same or more per month than people who drive.
“This study helped inform a reluctant property owner in my Utah county of the benefits of providing adequate pedestrian and bicycle access in front of their business.”
-Five County Association of Governments, Utah
Learn more about Examining Consumer Behavior and Travel Choices led by Kelly Clifton of Portland State University.