Reid Ewing

University of Utah | UOU · Department of City and Metropolitan Planning

Despite efforts to mitigate climate change by promoting active travel, limited research has focused on climate adaptation for active transportation (CAAT) initiatives. To address this gap, we conducted a qualitative study based on interviews with 30 planning professionals to uncover what CAAT projects U.S. cities are implementing, their barriers, a...

The significance of public transit in curbing greenhouse gas (GHG) emissions and reducing vehicle miles traveled (VMT) goes beyond its users. Investments in transit infrastructure, coupled with service enhancements and their consequential impacts on urban development (termed as indirect effects), have the potential to foster location efficiency. Th...

This research investigates the lane width standards and guidelines implemented by various State Departments of Transportation (DOTs) to reduce vehicle speeds and enhance road safety. Lane width reduction is often perceived as a strategy to mitigate speed and improve safety. Still, its effectiveness and implications vary across different contexts, i...

Introduction: Introducing new public transit systems impacts the surrounding built environment, and changes in the built environment can affect travel behavior. Prior research has yet to thoroughly conduct a comprehensive exploration of the influence of new investments in public modes of transit, particularly streetcars, on motor vehicle crashes oc...

One major challenge of a public transit system is first- and last-mile (FLM) connectivity. With the advent of smart technology and on-demand transportation services, shared micromobility is believed to provide a low-cost solution for bridging the first- and last-mile gap. However, several studies have arrived at mixed conclusions about the FLM achi...

This research investigates the lane width standards and guidelines implemented by various State Departments of Transportation (DOTs) to reduce vehicle speeds and enhance road safety. Lane width reduction is often perceived as a strategy to mitigate speed and improve safety. Still, its effectiveness and implications vary across different contexts, i...

As the adoption of battery electric vehicles (BEVs) surges into the spotlight of mainstream transportation networks, their implications for achieving Sustainable Development Goal 13 for climate action become ever more significant. Despite the symbolic optimism about their perceived potential to meet global climate targets, the discourse around legi...

Throughout the United States, Metropolitan Planning Organizations (MPOs) are increasingly attempting to shape local land use planning. Some MPOs have developed funding programs that redirect highway and road construction dollars to support less auto-centric community development - which we call Transportation and Land-Use Connection (TLC) programs....

Climate threats' increased frequency and intensity have recently severely threatened human health. In particular, racial/ethnic minority people have been disproportionately exposed to extreme heat and air pollution, but the cause of this is unclear. Green infrastructure can effectively mitigate heat waves and air pollution but is disproportionately...

Many of the larger US metropolitan regions promote polycentric development as a way of fostering livability, accessibility, and sustainability. Polycentric urban structures can increase transit ridership, promote active transportation, and decrease vehicle miles traveled (VMT) and CO2 emissions. Although many regions include ambitious polycentric a...

Our study compared observed traffic volumes in the Bus Rapid Transit (BRT-Light) corridor to those predicted using two different quasi-experimental methods. The first quasi-experimental design, referred to as interrupted time series, assumes the trends in traffic on BRT alignment from 2013 to 2017 continue through to 2019 after BRT-Light is in plac...

Reducing the lane width of urban arterials provides space for different street features, whereas selecting the appropriate lane width considering road safety is a concern. The major elements of this research are: a comprehensive literature review investigating the effects narrower travel lanes and other geometric designs have on speed, safety, and...

Despite the growing popularity and benefits of shared dockless e-scooters, there is controversy over whether this is an affordable travel mode for everyone. This paper explores the nonlinear relationship between shared dockless e-scooters and the location affordability of neighborhoods. By analyzing shared dockless e-scooter trip data collected bet...

With the population of older adults growing globally, this study asks the question: are older adults living in compact developments more active than those living in sprawling developments? Older adults can be deemed more active if they travel more in total or travel more by non-auto travel modes (such as walking, transit). By analyzing disaggregate...

Although growth management programs have many purposes, a critical one is to contain urban and suburban sprawl. Their efficacy in this regard is not well understood. In this paper, we review a comprehensive set of growth management tools, used by urban planners and policymakers to curb sprawl, starting with the history of the tool, then describing...

The theory of spatial mismatch states that the physical separation of people from their employment contributes to persistent unemployment and poverty. Although early research on spatial mismatch related more to housing discrimination, transit has long been considered a way to alleviate this issue by providing access to opportunity for disadvantaged...

Vehicle ownership is an important determinant of the travel demand forecasting process. Vehicle ownership models are used by policy makers to identify factors that affect vehicle miles traveled, and therefore address problems related to energy consumption, air pollution, and traffic congestion. For the conventional travel demand forecasting, it log...

This study addresses the question of parking supply and demand at transit-oriented developments (TODs) through comparative case studies of seven TODs in the U.S.A. As far as the authors can determine, this is one of the first studies to estimate peak parking generation rates for TODs. Developments are often characterized in relation to “D” variable...

Conventional four-step travel demand models, used by most metropolitan planning organizations (MPOs), state departments of transportation, and local planning agencies, are the basis for long-range transportation planning in the United States. Trip distribution—whether the trip is intrazonal (internal) or interzonal (external)—is one of the essentia...

The Institute of Transportation Engineers (ITE) guidelines serve as the most widely used reference for trip and parking generation estimates for any new development in the U.S.A. However, recent empirical studies question the efficacy of ITE guidelines in forecasting trip and parking generation in transit-oriented developments (TODs). Following the...

Problem, research strategy, and findings: The impact of density on emerging highly contagious infectious diseases has rarely been studied. In theory, dense areas lead to more face-to-face interaction among residents, which makes them potential hotspots for the rapid spread of pandemics. On the other hand, dense areas may have better access to healt...

Ride-sourcing services are getting more popular each year, and their markets are growing. Much has been speculated, but not much has been tested regarding the impacts of ride-sourcing services on the transportation system. In this study, we examine the relationship between ride-sourcing services and vehicle ownership of households, by using the mos...

This longitudinal study aimed to investigative the impacts of development density on the spread and mortality rates of COVID-19 in metropolitan counties in the United States. Multilevel Linear Modeling (MLM) were employed to model the infection rate and the mortality rate of COVID-19, accounting for the hierarchical (two-level) and longitudinal str...

Improving bus stops by providing shelters, seating, signage, and sidewalks is relatively inexpensive and popular among riders and local officials. Making such improvements, however, is not often a priority for U.S. transit providers because of competing demands for capital funds and a perception that amenities are not tied to measurable increases i...

Ride-sourcing services have made significant changes to the transportation system, essentially creating a new mode of transport, arguably with its own relative utility compared to the other standard modes. As ride-sourcing services have become more popular each year and their markets have grown, so have the publications related to the emergence of...

Problem, research strategy, and findings: The literature widely reports a statistical association between the built environment and obesity. What is less clear is the reason for the association. Is it environmental determinism—the effect of the built environment on individual behavior—with compact places inducing more physical activity and hence lo...

Problem, research strategy, and findings: The monocentric development pattern in the Alonso–Mills–Muth model underpinned theoretical discussions of urban form in the 1960s and 1970s and truly dominated theory up to the point when Joel Garreau published Edge City: Life on the New Frontier in the early 1990s. Monocentric development patterns remain d...

Urban design qualities have the potential to contribute to the sense of safety, comfort, engagement, and overall neighborhood satisfaction perceived by residents, thus can be related to higher property values. Yet, many of these urban design qualities are highly conceptual, require extensive data collection and are subject to various interpretation...

This study aims to improve a previously-developed methodology for predicting the traffic impacts of mixed-use developments (MXDs). In 31 diverse metropolitan regions across the United States, we collected consistent regional household travel survey data and computed built environment characteristics—D variables—of MXDs. Multilevel modeling (MLM) wa...

Metropolitan planning organizations (MPOs) providing funding for local land use planning is part of a growing trend which has so far received very little attention. This study surveyed a stratified sample of 30 U.S. MPOs weighted toward larger metropolitan areas. Of the 30 MPOs, about half were funding smart growth-oriented local land use planning...

The subjects of this comparative case study are Orenco Station, a transit-oriented development (TOD) in the Portland region, and Station Park, a transit-adjacent development (TAD) in Salt Lake City region. The peak parking demand at Orenco Station is less than one half the Institute of Transportation Engineers (ITE) suburban parking supply guidelin...

Urban design literature says that public open space in a station area could promote walking and other types of physical activity, enhance place attractiveness, and increase property values. In the context of station areas, however, there is a lack of empirical studies on the relationship between the presence of parks and sustainable travel behavior...

The planning literature has taken a recent interest in journal article citation counts, which are often used to measure the scholarly impact of articles, authors, or university departments. However, little is known about the factors that determine citation counts for planning-related articles. We find that citation counts in planning vary across pl...

Urban design qualities offer many benefits such as enhancing the visual aesthetics of streets and creating a memorable civic image of shared urban spaces. Urban design qualities also affect the level of pedestrian activity and the overall accessibility to urban amenities, thus could potentially be associated with property values. While these qualit...

Urban planners and designers believe that the built environment at various geographic scales affects pedestrian activity, but have limited empirical evidence at the street scale, to support their claims. We are just beginning to identify and measure the qualities that generate active street life, and this paper builds on the first few studies to do...

The monitoring of pedestrian activity is challenging, primarily because its traffic levels are typically lower and more variable than those of motorized vehicles. Compared with other on-the-ground observation tools, unmanned aerial vehicles (UAVs) could be suitable for counting and mapping pedestrians in a reliable and efficient way. Thus, this stu...

Guidelines for trip and parking generation in the United States come mainly from the Institute of Transportation Engineers (ITE). However, their trip and parking manuals focus on suburban locations with limited transit and pedestrian access. This study aims to determine how many fewer vehicle trips are generated and how much less parking demand is...

In recent years, the United States has had a relatively poor performance with respect to life expectancy compared to the other developed nations. Urban sprawl is one of the potential causes of the high rate of mortality in the United States. This study investigated cross-sectional associations between sprawl and life expectancy for metropolitan cou...

Transit-oriented development (TOD) has gained popularity worldwide as a sustainable form of urbanism by concentrating developments near a transit station so as to minimize auto-dependency and maximize ridership. Existing TOD studies, however, have limits in terms of small sample size and aggregate-level analysis. This study examines various travel...

Transit-oriented development (TOD) has gained popularity worldwide as a sustainable form of urbanism by concentrating developments near a transit station to minimize auto-dependency and maximize ridership. Existing behavior studies in the context of TOD, however, are limited in terms of small sample size, lack of consistency in TOD classification,...

From years of research, we know that compact development that is dense, diverse, well-designed, etc. produces fewer vehicle miles traveled (VMT) than sprawling development. But compact development also concentrates origins and destinations. No one has yet determined, using credible urban form metrics and credible congestion data, the net effect of...

While various observation techniques have been developed to measure park use or park-based physical activity, no study has used unmanned aerial vehicles (UAVs) to do so. Thus, this study develops a new observation method that uses UAVs to survey park-based physical activity. This study tests the inter-rater reliability and criterion validity of the...

The decision on how best to allocate land around transit stations is a debated topic, with transit officials often opting for park-and-ride lots over active uses such as multifamily housing, office, and retail organized into transit-oriented developments (TODs). In this study, we identify the ten best self-contained TODs in ten regions across Unite...

Transit-oriented development (TOD) has gained popularity worldwide as a sustainable form of urbanism; it concentrates development near a transit station so as to reduce auto-dependency and increase ridership. Existing travel behavior studies in the context of TOD, however, are limited in terms of small sample size, inconsistent TOD classification m...

Transportation-planning researchers have long argued that the end goal of a transportation system is increasing accessibility, or opportunities for individuals to meet their daily needs, but that US practice tends to focus on increasing mobility, or opportunities to travel farther and faster. This study finds evidence that the gap between theory an...

This study proposes a home-based walk trip generation model, based on the built environment around households, controlling for sociodemographic influences. Two-stage hurdle models are estimated based on a household travel survey in Portland, Oregon. The first stage predicts the probability of households making any home-based walk trips. The second...

Guidelines for trip and parking generation in the United States come mainly from the Institute of Transportation Engineers (ITE). However, their trip and parking manuals focus on suburban locations with limited transit and pedestrian access. This study aims to determine how many fewer vehicle trips are generated at transit-oriented developments (TO...

This study examines how the network accessibility effect and the built environment have an impact on the mode share for transit commuting across transit stations. Data is examined from 4400 fixed-guideway transit stations across the United States. We use a multiple-level model to account for variables at both the regional level and the neighborhood...

This study tests four hypotheses related to the much-cited work on density and automobile dependence by Newman and Kenworthy, using multivariate analysis and data for 157 large US urbanized areas. We find that density alone explains only a small fraction of the variation in vehicle miles traveled (VMT), and many confounders account for the differen...

The majority of people now live in an urban (or suburban) environment. The built (material) environment, its vehicular and pedestrian infrastructure, buildings, and public realm places, are the places used for working, living, and recreating. The environment currently favors and facilitates motorized vehicles generally, and private automobiles espe...

Using a health impact assessment framework, we estimated the population health effects arising from alternative land-use and transport policy initiatives in six cities. Land-use changes were modelled to reflect a compact city in which land-use density and diversity were increased and distances to public transport were reduced to produce low motoris...

This study presents a comparison of housing and transportation costs (H+T) in 4,399 fixed-route transit station areas across the United States. Each station area is classified as a transit-oriented development (TOD), hybrid, or transit-adjacent development (TAD) based on walkability and housing density targets. Station areas with a Walk Score of 70...

Contrary to the general perception, the United States has a much more class-bound society than other wealthy countries. The chance of upward mobility for Americans is just half that of the citizens of the Denmark and many other European countries. In addition to other influences, the built environment may contribute to the low rate of upward mobili...

This article assesses the affordability of U.S. Department of Housing and Urban Development (HUD) rental assistance properties from the perspective of transportation costs. HUD housing is, by definition, affordable from the standpoint of housing costs due to limits on the amounts renters are required to pay. However, there are no such limitations o...

The need for innovative regional transportation planning has grown as metropolitan areas consider the impact of congestion reduction efforts on induced demand, public health, and fossil fuel use and climate change. Although conventional practice among metropolitan planning organizations (MPOs) is to simply expand roadway capacity to relieve congest...

Although transit accessibility premiums have been rigorously studied at the local and regional levels for more than 40 years, drawing conclusions about premiums on a national scale requires a meta-analysis. Estimating effect size is a primary purpose of a meta-analysis. Effect size was calculated in 2007 by using pre-2003 studies but has not been s...