Photo source: www.pedbikeimages.org / Laura Sandt
Relationship to public health
The ability to reach everyday destinations is critical to improving health. For example, people need access to grocery stores that provide healthy food, healthcare services for preventive care, and jobs and educational opportunities that contribute to economic well-being. The transportation system plays an important role in ensuring that travelers can reach everyday destinations safely, reliably, and conveniently.
Street design, the presence and quality of bicycle and pedestrian infrastructure, bus stop shelters and signage, and the design of the street grid influence neighborhood-level access to destinations such as grocery stores, schools, parks, and doctors’ offices.
At the regional level, efficient roadways and public transportation service affect access to jobs, education, and healthcare opportunities. Public transportation service is particularly important to ensure access for people unable to drive, such as members of low-income households, children, individuals with disabilities, and older adults.
Access to destinations is one of the key factors determining how much time people spend driving. Increasing access can reduce the negative health effects of long car trips, such as physical inactivity and high blood pressure.
Some ways transportation agencies can increase connectivity include the following:
- Integrating transportation and land use planning to locate major commercial and institutional activity centers in highly accessible areas, such as public transportation hubs and central business districts.
- Reducing distances between key destinations required to satisfy daily needs so that walking or bicycling are attractive and practical options for frequent trips that take place close to home.
- Improving local pedestrian and bicycle infrastructure and parking, particularly at key access points to neighborhood destinations. This might include pedestrian crossings on busy main roads, public transportation stops and stations, sidewalks throughout shopping centers, and paths that provide safe access to schools.
- Managing the transportation system to reduce travel times to destinations through measures such as improved incident response, public transportation signal prioritization, and congestion management.
Related indicators in the THT
Access to destinations is typically measured at the neighborhood level. The metro-area and state-level indicators included in the THT do not directly measure connectivity. However, many of these indicators can be used to describe overall access and relative access across different travel modes.
Commute mode share describes the modes of transportation that workers use to access their jobs.
Person miles traveled by mode describes the relative distance that people travel using particular modes. It can serve as an indicator of the relative accessibility offered by different modes.
Vehicle miles traveled (VMT) per capita provides a measure of how much the average person drives. Lower VMT per capita can indicate shorter driving distances or good access to destinations via alternatives to driving.
Land use mix describes whether a community has different destinations available within walking distance. Diverse local land uses allow residents to make more trips by foot or by bicycle.
Complete streets policies describe the presence of policies to create streets that offer access to destinations via public transportation, bicycle, and foot.
Use of federal funds for bicycle and pedestrian efforts describes the extent to which transportation agencies are using discretionary federal funding to create or improve facilities that offer safe neighborhood-level access to shops and services.
Public transportation trips per capita describes how often people ride public transportation. High levels of public transportation use can indicate that public transportation provides good accessibility to destinations throughout a region.
The EPA Smart Location Database provides geographic information systems (GIS) data on road and public transportation accessibility variables. These include
- the total amount and percentage of regional jobs available within a 45-minute motor vehicle or public transportation trip from residential neighborhoods,
- the total number of workers within a 45-minute motor vehicle or public transportation trip from employment centers, and
- the proportion of total regional jobs located in the central business district, which is typically the area best served by public transportation and motor vehicle.
The Location Affordability Index estimates the combined costs of housing and transportation at the U.S. Census block-group level. Index data are calculated for areas that include 94% of where the U.S. population lives.
The Accessibility Observatory at the University of Minnesota provides research and data on the ability of people to reach the destinations they must visit to meet their needs. The site includes a number of Access Across America research publications.
The U.S. Department of Agriculture’s Food Access Research Atlas provides census tract-level data on overall access to grocery stores, and for low-income and car-free households. It presents a spatial overview of food access indicators for low-income and other census tracts using different measures of supermarket accessibility; provides food access data for populations within census tracts; and offers census-tract-level data on food access that can be downloaded for community planning or research purposes.
The Trust for Public Land's Park Score tool provides information on the share of the population located within a 10-minute walk of a park for the 75 largest U.S. cities. The tool provides information for the overall population and for different age and income groups.
The authors of this study find that longer commutes are associated with reduced physical activity and increased body mass index and blood pressure.
Hoehner C, Barlow C, Allen P, Schooman M. Commuting distance, cardiorespiratory fitness, and metabolic risk. American Journal of Preventive Medicine 2012;42(6):571-578.
This study examines the relationship between body weight and distance to groceries. It finds that longer distances to grocery stores are associated with increased body mass index.
Inagami S, Cohen DA, Finch BK, Asch SM. You are where you shop: grocery store locations, weight, and neighborhoods. American Journal of Preventive Medicine 2006;31(1):10-17.
This study examines the relationship between fruit and vegetable intake and local access to grocery stores. The authors find that fruit and vegetable intake increases by 32% for each additional supermarket in the census tract for black Americans and 11% for white Americans.
Morland K, Wing S, Diez Roux A. The contextual effect of the local food environment on residents’ diets: the atherosclerosis risk in communities study. American Journal of Public Health 2002;92(11):1761–1767.
This comprehensive review of research linking park access to health cites multiple studies that have found a strong relationship between physical activity and access to parks, particularly for children.
Godbey G, Mowen A. 2010. The benefits of physical activity provided by park and recreation services: the scientific evidence. National Recreation and Parks Association.
This report examines the relationship between several transportation variables and employment outcomes. It finds that car ownership and residence near public transportation are key factors that increase the likelihood of return to work.
Cervero R, Sandoval O, Landis J. Transportation as a stimulus of welfare-to-work: private versus public mobility. Journal of Planning Education and Research 2002;22(1):50-63.
The authors report findings from a telephone survey of why parents drive their children to schools that are within walking or bicycling distance (less than 2 miles). It offers recommendations for how Safe Routes to School program administrators can address issues related to parental convenience and time constraints.
McDonald N, Aalborg A. Why parents drive children to school: implications for safe routes to school programs. Journal of the American Planning Association 2009;75(3):331-342.
This report summarizes research on the social, community, and environmental characteristics that determine whether children use active transportation to get to school and provides recommendations for future practice.
Davison KK, Werder JL, Lawson CT. Children’s active commuting to school: current knowledge and future directions. Preventing Chronic Disease 2008;5(3):A100.
This report examines the relationship between travel behavior and several built environment variables. It finds that increasing accessibility to jobs by auto and public transportation can reduce driving, and that people walk more in neighborhoods with destinations located within 1 mile.
Ewing R, Cervero R. Travel and the built environment: a meta-analysis. Journal of the American Planning Association 2010;76(3):1-30.
Access to Destinations consists of 11 studies in three subject areas. The research takes a new approach to understanding how people use the transportation system and how transportation and land use interact. At the heart of this approach is the concept of accessibility: the ability of people to reach the destinations they need to visit to meet their needs.
Levinson, D. 2010.Measuring What Matters: Access to Destinations. Center for Transportation Studies. University of Minnesota.