conference paper

A Longitudinal Analysis of the Heterogeneous Changes in Travel Behaviors in Response to the COVID-19 Pandemic in the United States

Publication Date

January 5, 2022

Associated Project

Assessing Temporary and Long-Lasting Impacts of the COVID-19 Pandemic on Travel in California

Areas of Expertise

Travel Behavior, Land Use, & the Built Environment

View conference paper

Abstract

The COVID-19 pandemic has caused a huge disruption worldwide with direct and indirect effects on travel behavior. In response to extensive community spread and potential risk of infection, during the early stage of the pandemic, many state and local governments implemented non-pharmaceutical interventions that restricted non-essential travel for residents. This study evaluates the impacts of the pandemic on mobility by analyzing micro panel data (N = 1,274) collected in the United States via online surveys in two periods, before and during the early phase of the pandemic. The panel makes it possible to observe initial trends in travel behavior change, adoption of online shopping, active travel, and use of shared mobility services. This analysis intends to document a high-level overview of the initial impacts to spur future research to dive deeper into these topics. With the analysis of the panel data, substantial shifts are found from physical commutes to teleworking, more adoption of e-shopping and home delivery services, more frequent trips by walking and biking for leisure purposes, and changes in ride-hailing use with substantial variations across socioeconomic groups. The social and environmental implications of these findings are discussed and suggestions for effective policy and directions for future research are made in the conclusion.

Related Publications

published journal article

Teleworkers and Physical Commuters During the COVID-19 Pandemic: the Change in Mobility Related Attitudes and the Intention to Telecommute in the Future

research report

Changes in Activity-Travel Patterns and Vehicle Ownership During the COVID-19 Pandemic in California

policy brief

Assessing the Shift to Remote and Hybrid Work in California throughout the COVID-19 Pandemic

research report

Barriers to Reducing the Carbon Footprint of Transportation Part 2: Investigating Evolving Travel Behaviors in the Post-Pandemic Period in California

published journal article

Longitudinal Analysis of COVID-19 Impacts on Mobility: An Early Snapshot of the Emerging Changes in Travel Behavior

conference paper

Latent Class Analysis of Changes in the Use of Public Transportation in The Greater Los Angeles Region during the COVID-19 Pandemic

policy brief

By Transit, By-Right: Impacts of Housing Development Approval Processes on Transit-Supportive Density

Publication Date

January 1, 2022

Associated Project

By Transit, By-Right: How Housing Development Approval Processes Can Support Higher Transit-Friendly Density

Author(s)

Michael Manville, Nolan Gray, Paavo Monkkonen, Shane Phillips

Areas of Expertise

Travel Behavior, Land Use, & the Built Environment

View policy brief

Abstract

Transit ridership in Los Angeles County has fallen
consistently over the past decade despite major investments
in public transportation. The reasons for this outcome vary,
but one likely culprit is the county’s built environment,
which is generally auto-oriented and low-density. Allowing
more, higher-density housing to be built near transit could
help increase transit ridership, but this solution faces two
obstacles. The first and largest obstacle is widespread
restrictions on multifamily development. The second, and
the focus of this brief, is the housing development process:
Even if new multifamily housing is allowed on a site, a
complicated, lengthy or unpredictable process could still
discourage its production.
Development processes are often categorized as “by-right,”
meaning developments are approved or not based on
whether they meet certain objective requirements, or as
“discretionary” — negotiated project-by-project in a back-
and-forth between city officials and builders.
Compared to discretionary processes, by-right processes
should in theory reduce the cost, delay, and uncertainty
associated with securing approvals, allowing homes to be
delivered more quickly and less expensively. It has been
difficult to test this hypothesis, however, because by-right
approvals are rare in cities where housing is in high demand
and are usually reserved for smaller projects.
The Transit Oriented Communities (TOC) density bonus
program, implemented in Los Angeles in 2017, changed the
city’s development process for certain projects, creating
a by-right approval pathway for many projects that would
have previously been discretionary, and streamlining
the entitlement process for many others that remained
discretionary. We take advantage of this program to measure
the impact of by-right and streamlined processes on project
approval times, with shorter times serving as a proxy for less
costly and potentially less risky housing development. For
each project, we determine the entitlement pathway, total
approval time, size, subsidy status, parking provided, certain
characteristics of the parcel, neighborhood characteristics
such as median household income and distance from the
central business district, and its location relative to the
TOC program boundaries. Using a multivariate analysis, we
compare approval times for each category, with and without
controls for many project and neighborhood characteristics.

Related Publications

published journal article

Does Discretion Delay Development?

published journal article

What travel modes do shared e-scooters displace? A review of recent research findings

Publication Date

January 1, 2022

Associated Project

What travel modes do shared e-scooters displace? A review of recent research findings

Areas of Expertise

Public Transit, Shared Mobility, & Active Transportation Travel Behavior, Land Use, & the Built Environment

View published journal article

Abstract

The impacts of shared e-scooters on modal shifts have received increased attention in recent years. This study provides a review of the literature for modal shifts in the US and other countries. The profile of shared e-scooter users is rather similar to that of station-based and free-floating bikeshare programs. The empirical data reveal that people use shared e-scooters in place of cars at substantial rates, especially in many US cities, which suggests that in many locations shared e-scooters may be a good strategy for reducing car dependence. The use of shared e-scooters as a complement to public transit varies highly by city, highlighting how technology, regulations, and incentives may be needed in some cities to ensure modal integration and harvest the potential societal benefits from the introduction of shared e-scooters.

research report

Brace for Impact: The Environmental and Economic Effects of Shifting Passenger Travel from Airplanes to High-Speed Rail

Publication Date

January 1, 2022

Associated Project

Brace for Impact: The Environmental and Economic Effects of Shifting Passenger Travel from Airplanes to High-Speed Rail

Author(s)

Jason Karpman

Areas of Expertise

Public Transit, Shared Mobility, & Active Transportation Travel Behavior, Land Use, & the Built Environment

View research report

Abstract

This research synthesis surveys recent literature from 2011 to 2020 on the environmental and economic effects of high-speed rail (HSR) projects from across the globe, with relevant lessons for implementation of the California High-Speed Rail (CAHSR) project. Recent literature shows that—under the right conditions—HSR can lead to both environmental and economic gains across a variety of metrics. To maximize environmental gains, HSR ridership needs to be high, energy propulsion must be powered largely by renewables, and displaced demand for intrastate air travel must not be replaced by longer-haul flights. For there to be economic gains, cities connected by HSR must play complementary roles, rather than competitive ones, within the economy. Otherwise, economic benefits will be consolidated in core cities along HSR routes at the expense of intermediate cities, and efficiencies from agglomeration may lead to an overall decline in employment and economic value added. This synthesis closes with some recommendations for future research questions that can inform the development or refinement of policies that support the successful implementation of CAHSR.

Related Publications

policy brief

Cutting Emissions from Aviation: Is High-Speed Rail the Answer?

published journal article

An L.A. story: The impact of housing costs on commuting

Publication Date

December 14, 2021

Associated Project

Understanding the Impact of Housing Costs in California on Commute Length in Terms of Travel Time and Distance

Areas of Expertise

Travel Behavior, Land Use, & the Built Environment

View published journal article

Abstract

The empirical impact of housing costs on commuting is still relatively poorly understood. This impact is especially salient in California given the state’s notoriously high housing costs, which have forced many lower- and middle-class households to move inland in search of affordable housing at the cost of longer commutes. To investigate this linkage, we relied on Generalized Structural Equation Modeling and analyzed 2012 CHTS data for Los Angeles County – the most populous county in the U.S. Our model, which jointly explains commuting distance and time, accounts for residential self-selection and car use endogeneity, while controlling for household characteristics and land use around residences and workplaces. We find that households who can afford more expensive neighborhoods have shorter commute distances (−2.3% and − 3.1% per additional $100 k to median home values around workplaces and residences respectively). Job density, distance to the CBD, and land-use diversity around workplaces have a relatively greater impact on commuting than the corresponding variables around commuters’ residences. Compared to non-Hispanics, Hispanic workers commute longer distances (+3.5%), and so do African American (+5.1%) and Asian (+2.0%) workers compared to Caucasians, while college-educated workers have shorter (−2.6% to −3.6%) commutes. Furthermore, commuters in the top income brackets tend to have faster commutes than lower-income workers. Finally, women’s commutes are ~41% shorter than men’s, possibly because they are balancing work with domestic responsibilities. A better understanding of the determinants of commuting is critical to inform housing and transportation policy, improve the health of commuters, reduce air pollution, and achieve climate goals.

Related Publications

policy brief

An L.A. Story: The Impact of Housing Costs on Commuting

published journal article

Estimating short-term travel demand models that incorporate personally owned autonomous vehicles

Publication Date

November 11, 2021

Associated Project

Simulating Life with Personally-Owned Autonomous Vehicles through a Naturalistic Experiment with Personal Drivers

Areas of Expertise

Intelligent Transportation Systems, Emerging Technologies, & Big Data Travel Behavior, Land Use, & the Built Environment

View published journal article

Abstract

We estimated travel demand models that incorporate a private autonomous vehicle (AV) option using revealed preference data in which personal chauffeurs simulated a personally owned AV. We investigated four components of activity-based models (ABM): activity pattern and primary destination choice, mode choice, and time of day. We compared the chauffeur week models (“AV future”) to the non-chauffeur week models (current conditions). We found no statistically significant differences in parameters of the individual activity pattern, time of day, or destination choice. For mode choice, however, while the auto constant did not change, the mean value of time decreased by 60%. As the destination choice model included the mode choice log sum, this results in longer average tour lengths. Moreover, while the trip-making propensity of individuals did not change significantly, there was a 25% increase in systemwide trips due to “AVs” (chauffeurs) being sent on errands. This points to the importance of incorporating zero-occupancy vehicle (ZOV) trips into the ABM framework. Our findings suggest that these can be incorporated via the standard ABM development process by adding as additional model components ZOV home-based tours and ZOV subtours. Relatedly, as inter-regional travel is modeled outside the ABM framework, our results indicated that modifications should be made to account for the increase in inter-regional tours, which were 54% more frequent during chauffeur weeks. While these results are from a relatively small sample of 71 individuals, they are the first such travel demand estimation results available from a field experiment, and further studies can build on our framework.

Related Publications

research report

Simulating Life with Personally-Owned Autonomous Vehicles through a Naturalistic Experiment with Personal Drivers

policy brief

Real-World Simulations of Life with an Autonomous Vehicle Suggest Increased Mobility and Vehicle Travel

published journal article

Glimpse of the Future: Simulating Life with Personally Owned Autonomous Vehicles and Their Implications on Travel Behaviors

policy brief

Real-World Simulations of Life with an Autonomous Vehicle Suggest Increased Mobility and Vehicle Travel

Publication Date

November 1, 2021

Associated Project

Simulating Life with Personally-Owned Autonomous Vehicles through a Naturalistic Experiment with Personal Drivers

Author(s)

Giovanni Circella, Jai Malik, Joan Walker, Mustapha Harb

Areas of Expertise

Intelligent Transportation Systems, Emerging Technologies, & Big Data Travel Behavior, Land Use, & the Built Environment

View policy brief

Abstract

Fully autonomous vehicles are expected to have a profound effect on travel behavior. The technology will provide convenience and better mobility for many, allowing owners to perform other tasks while traveling, summon their vehicles from a distance, and send vehicles off to complete tasks without them. These travel behaviors could lead to increases in vehicle miles traveled that will have major implications for traffic congestion and pollution. To estimate the extent to which travel behavior will change, researchers and planners have typically relied on adjustments to existing travel simulations or on surveys asking people how they would change their behavior in a hypothetical autonomous vehicle future. Researchers at UC Berkeley and UC Davis used a new approach to understand the potential influence of autonomous vehicles on travel behavior by conducting the first naturalistic experiment mimicking the effect of autonomous vehicle ownership. Private chauffeurs were provided to 43 households in the Sacramento, California region for one or two weeks. By taking over driving duties for the household, the private chauffeurs served the household as an autonomous vehicle would. Researchers tracked household travel prior to, during, and after the week(s) with access to the chauffeur service.

Related Publications

research report

Simulating Life with Personally-Owned Autonomous Vehicles through a Naturalistic Experiment with Personal Drivers

published journal article

Estimating short-term travel demand models that incorporate personally owned autonomous vehicles

published journal article

Glimpse of the Future: Simulating Life with Personally Owned Autonomous Vehicles and Their Implications on Travel Behaviors

published journal article

Glimpse of the Future: Simulating Life with Personally Owned Autonomous Vehicles and Their Implications on Travel Behaviors

Publication Date

October 31, 2021

Associated Project

Simulating Life with Personally-Owned Autonomous Vehicles through a Naturalistic Experiment with Personal Drivers

Areas of Expertise

Intelligent Transportation Systems, Emerging Technologies, & Big Data Travel Behavior, Land Use, & the Built Environment

View published journal article

Abstract

To explore potential travel behavior shifts induced by personally owned, fully autonomous vehicles (AVs), we ran an experiment that provided personal chauffeurs to 43 households in the Sacramento region to simulate life with an AV. Like an advanced AV, the chauffeurs took over driving duties. Households were recruited from the 2018 Sacramento household travel survey sample. Sampling was stratified by weekly vehicle miles traveled (VMT), and households were selected to be diverse by demographics, modal preferences, mobility barriers, and residential location. Thirty-four households received 60 hours of chauffeur service for 1 week, and nine households received 60 hours per week for 2 weeks. Smartphone-based travel diaries were recorded for the chauffeur week(s), 1 week before, and 1 week after. During the chauffeur week, the overall systemwide VMT (summing across all sampled households) increased by 60%, over half of which came from “zero-occupancy vehicle” (ZOV) trips (when the chauffeur was the only occupant). The number of trips made in the system increased by 25%, with ZOV trips accounting for 85% of these additional trips. There was a shift away from transit, ride-hailing, biking, and walking trips, which dropped by 70%, 55%, 38%, and 10%, respectively. Households with mobility barriers and those with less auto dependency had the greatest percent increase in VMT, whereas higher VMT households and families with children had the lowest. The results highlight how AVs can enhance mobility, but also caution against the potential detrimental effects on the transportation system and the need to regulate AVs and ZOVs.

Related Publications

research report

Simulating Life with Personally-Owned Autonomous Vehicles through a Naturalistic Experiment with Personal Drivers

published journal article

Estimating short-term travel demand models that incorporate personally owned autonomous vehicles

policy brief

Real-World Simulations of Life with an Autonomous Vehicle Suggest Increased Mobility and Vehicle Travel

research report

Assessing the Incorporation of Racial Equity into Analytical and Modeling Practices in Transportation Planning

Publication Date

November 1, 2021

Associated Project

Assessing the Incorporation of Racial Equity into Analytical and Modeling Practices in Transportation Planning

Author(s)

Chelsey Byrant, Chhandara Pech, Jared Tadayon, Mark Garrett, Paul Ong, Silvia González

Areas of Expertise

Safety, Public Health, & Mobility Justice Travel Behavior, Land Use, & the Built Environment

View research report

Abstract

This report examines if and to what extent state-level transportation departments in four states incorporate race and equity considerations into transportation planning technical analyses and modeling practices, particularly for long-range transportation plans, and how such equity-infused practices can be improved. The research team examined relevant literature, reviewed statewide long-range transportation plans for California and three other states, consulted with other experts, and conducted interviews with scholars and knowledgeable agency staff and practitioners. The findings indicate widespread acknowledgment that racial disparities in transportation exist, and state agencies have expressed a strong commitment to redressing the inequalities. However, while there has been progress in creating analytical equity tools to assess transportation projects and programs, they lack standardization. There have also been few noticeable revisions to existing regional transportation planning models to incorporate equity, and the profession lags behind what is technically possible based on the work of academic researchers. Technical staff need better training in regard to equity issues and agencies should encourage greater collaboration between equity and analytical units to develop and improve frameworks to assess equity performance in plans, programs, and projects.

published journal article

Gender differences in elderly mobility in the United States

Publication Date

October 27, 2021

Associated Project

Mobility of Older Adults in California: In the Era of Shared Mobility

Areas of Expertise

Safety, Public Health, & Mobility Justice Travel Behavior, Land Use, & the Built Environment

View published journal article

Abstract

Mobility is a critical element of one’s quality of life regardless of one’s age. Although the challenges for women are more significant than those for men as they age, far less is known about the gender differences in mobility patterns of older adults, especially in the United States (US) context. This paper reports on a study that examined potential gender gaps in mobility patterns of older adults (aged 65 years and over) in the US by analyzing data from the 2017 National Household Travel Survey. Elderly respondents were first classified into one of six clusters based on socio-demographic variables. A Structural Equation Model (SEM) was then estimated and showed that gender gaps existed in the mobility patterns of the elderly, and the differences were diverse across the different clusters. The most substantial gender gap was found in the Senior Elder with Medical Condition(s) cluster, followed by the High-income Workers cluster and the Middle-income Urban Residents cluster. In contrast, females in the Low-Income Single Elder cluster enjoyed statistically significant positive mobility differences with their male counterparts. Our results also found that female elderly in the Senior Elder with Medical Condition(s) and the Low-income Family Elder clusters suffered most after the cessation of driving, with the largest mobility gender gap in the Middle-income Urban Resident cluster. This study will help transportation planners and policymakers understand gender and other socio-demographic differences in elderly mobility. Thus, it will facilitate the development of measures to improve elderly mobility and reduce gender gaps by recognizing and addressing specific target groups’ mobility characteristics and needs rather than treating the elderly as a single potential user group.

Related Publications

published journal article