New Tool Evaluates Health and Equity Impacts of Sacramento’s Regional Transportation Plans

There is growing value in developing regional transportation plans that foster safer, healthier, and more environmentally sustainable communities. Greater rates of active travel (walking and biking) can lead to improved health outcomes due to increases in physical activity and air quality improvements, although they also increase risks of traffic injury. Analytical tools that evaluate the distribution of outcomes and the tradeoffs between transportation plan alternatives are needed to inform public debate and ensure that gains in some health outcomes are not being undermined by losses elsewhere. Additionally, there is a need to evaluate the impacts of transportation plans on different demographic groups to work toward more equitable outcomes.This policy brief summarizes findings from a project that created a tool to investigate the distribution of public health impacts resulting from the implementation of a regional transportation plan in the six-county Sacramento Area Council of Governments (SACOG) region.View the NCST Project Webpag

Development of Fine-Grained Spatial Resolution for an Integrated Health Impacts Assessment Tool for the Sacramento Region

Understanding the public health impacts of transportation plans can inform decision making and project prioritization. Because each plan and regional context is different, there is a need for site-specific methods to assess the extent and distribution of health impacts of changes to a region’s transportation system. To fill this need, researchers have developed the Integrated Transport and Health Impact Model (ITHIM), which predicts the public health impacts of transportation and land use scenarios from expected changes in air quality, traffic safety, and physical activity. However, current transportation health impact assessment models (including ITHIM) operate at coarse geographic scales (e.g., region or county) to quantify health changes. This research builds on previous work using ITHIM to generate demographically explicit health outcomes to provide neighborhood-level estimates of public health changes predicted from transportation plan scenarios in Sacramento, California.We assess the impacts of regional transportation plan scenarios on public health via changes in traffic injury and physical activity. Zip-code level results are mapped using a customizable web interface. Illustrative results indicate that the adopted regional transportation plan will lead to improved health outcomes, largely driven by the benefits of increased physical activity. However, these estimates vary widely across the region, with some communities expected to experience adverse impacts and others obtaining higher levels of benefit. We note that some of the variation may be the result of modeling noise, and we identify promising avenues for improving the robustness of estimates at small spatial scales.Disaggregation is important from sustainability and equity perspectives to determine the locations where and populations for whom the physical activity benefits of non-motorized transportation are outweighed by increased exposure to the risk of air pollution and injury or death. Providing an accessible, web-based tool to illustrate the effects of transportation plans and in communities across a region has the potential to elevate health and equity considerations in transportation decision making. The methods developed in this study can be refined and improved and applied elsewhere by modifying the source code, which is publicly available.View the NCST Project Webpag

A Census of the US Near-Roadway Population: Public Health and Environmental Justice Considerations

This study estimates the size and distribution of the population living near high volume roads in the US, investigates race and income disparities in these near roadway populations, and considers the coverage of the national ambient air quality monitoring network. Every US census block is classified by traffic density and proximity to roads falling within several traffic volume ranges using year 2008 traffic data and the 2010 and 2000 US Census. The results indicate that 19% of the population lives near high volume roads. Nationally, greater traffic volume and density are associated with larger shares of non-white residents and lower median household incomes. Analysis at the county level finds wide variation in the size of near roadway populations and the severity of environmental justice concerns. Every state, however, has some population living near a high volume road and 84% of counties show some level of disparity. The results also suggest that most counties with residents living near high volume roads do not have a co-located regulatory air quality monitor

Travel and the Built Environment in Rural Communities

Reducing greenhouse gas (GHG) emissions from transportation poses a significant challenge in rural communities and at the edges of metropolitan areas where rural and urban populations meet, otherwise known as exurban fringe. Populations living in these areas rely more heavily on personal vehicle travel than nonrural populations do and are more likely to have trouble getting to and from important destinations. One approach to curtailing transportation GHG emissions is through land use planning, for example by directing population growth into compact, walkable communities with access to transit. However, nearly all research to date on this topic has focused on urban and suburban areas, leaving decision-makers in exurban and rural communities with little guidance for how to effectively reduce GHGs through changes to land use and development in their communities.Researchers at the University of Vermont sought to answer the question: is the relationship between travel and the built environment the same in urban and rural areas? They analyzed nationwide data from the United States Federal Highway Administration on nearly 110,000 people and detailed information on land use and development from the United States Environmental Protection Agency Smart Location Database. They determined what aspects of the built environment in different types of locations (urban, rural, etc.) were associated with sustainable travel behaviors such as greater rates of walking and biking, less reliance on automobile travel, and fewer vehicle miles traveled or VMT, which is the number of miles driven in a car. This policy brief summarizes the findings from that research and provides policy implications.View the NCST Project Webpag

Estimating exposure to fine particulate matter emissions from vehicle traffic: Exposure misclassification and daily activity patterns in a large, sprawling region

Vehicle traffic is responsible for a significant portion of toxic air pollution in urban areas that has been linked to a wide range of adverse health outcomes. Most vehicle air quality analyses used for transportation planning and health effect studies estimate exposure from the measured or modeled concentration of an air pollutant at a person’s home. This study evaluates exposure to fine particulate matter from vehicle traffic and the magnitude and cause of exposure misclassification that result from not accounting for population mobility during the day in a large, sprawling region. We develop a dynamic exposure model by integrating activity-based travel demand, vehicle emission, and air dispersion models to evaluate the magnitude, components and spatial patterns of vehicle exposure misclassification in the Atlanta, Georgia metropolitan area. Overall, we find that population exposure estimates increase by 51% when population mobility is accounted for. Errors are much larger in suburban and rural areas where exposure is underestimated while exposure is may also be overestimated near high volume roadways and in the urban core. Exposure while at work and traveling account for much of the error. We find much larger errors than prior studies, all of which have focused on more compact urban regions. Since many people spend a large part of their day away from their homes and vehicle emissions are known to create “hotspots” along roadways, home-based exposure is unlikely to be a robust estimator of a person’s actual exposure. Accounting for population mobility in vehicle emission exposure studies may reveal more effective mitigation strategies, important differences in exposure between population groups with different travel patterns, and reduce exposure misclassification in health studies

A Data Driven Analysis of Rural Equity and Cost Concerns for Mileage-Based User Fees in Vermont

Examining substitutes to the current state and federal gasoline and diesel fuel excise taxes has become a pressing issue, exacerbated by the rise of high efficiency and alternative fuel vehicles threatening the revenue generating capacity of these taxes. A mileage-based user fee has been frequently proposed in the literature as an alternative which would offer greater benefits to rural and low-income populations than to urban and higher income populations. However, most prior analyses relied on small data sets and aggregated data. This study examined the impact of replacing the Vermont state fuels tax with a revenue-neutral mileage-based user fee using mileage and fuel economy data for over 300,000 registered passenger vehicles. We find that, on average, Vermont households would pay an additional $23 per year, with rural households and low-income households facing smaller tax burdens than their urban and high-income counterparts. The impacts of a$180 flat fee replacing the Vermont state motor fuels tax was also examined due to state interest. Findings indicate a flat fee would result in much larger price fluctuations, with most households paying an additional $47 per year. The disaggregated data approach presented here directly addresses public misconceptions of inequitable cost differences and provides context for public education campaigns to garner mileage-based user fee policy support. Based on our results, there is political ground for further research into the implementation of a mileage-based user fee, including the logistics of an administrative transition to mileage charging and the associated program implementation and technological costs

Policy Brief: Mode Constrained Travel at UVM: Travel Preferences, Barriers, and Policy Implications

One of the objectives of the Chittenden Area Transportation Management Association (CATMA) is to encourage commuters to shift from driving to more sustainable travel modes such as walking, bicycling, and public transit. To understand barriers to switching to greener modes among UVM employees, we evaluated CATMA’s 2019 Transportation Survey to compare the modes that UVM employees currently use to the modes that they prefer to use. We also identify barriers to switching to preferred travel modes. The results show untapped potential for divesting from driving, with respondents citing several mitigatable barriers

Access to Secure Ballot Drop-off Locations in Texas

Safe access to voting during the Covid-19 pandemic was a concern across the US. In Texas, a push for mail-in voting during the November 2020 presidential election was significantly scaled back when the governor restricted each county to one secure ballot drop-off location. We evaluate the effect of this change, finding that it increased travel times to drop-off locations for drivers and public transit users by 18 and 32 minutes, respectively, in the most affected county. When evaluated across the state, the policy had a disproportionate effect on eligible Asian, Black, and Latinx voters