policy brief

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

Publication Date

September 1, 2024

Associated Project

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

Author(s)

Jean-Daniel Saphores, Md Rabiul Islam

Areas of Expertise

Travel Behavior, Land Use, & the Built Environment

View policy brief

Abstract

Concerns about the environmental impacts of transportation have made reducing vehicle miles traveled (VMT) a policy priority. One way to decrease VMT is to decrease the length of commuting trips, and to get commuters out of their private vehicles. Unfortunately, the average one-way commute keeps getting longer in the U.S., increasing from 25.1 to 27.6 minutes between 2005 and 2019. The percentage of work trips made by private vehicle has also soared, jumping from 66.9 percent in 1960 to 84.8 percent in 2019. As commuting typically occurs during traffic peaks, it is a major contributor to congestion and air pollution.

Related Publications

published journal article | December 14, 2021

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

research report

Assessing the Potential for Densification and VMT Reduction in Areas without Rail Transit Access

Publication Date

September 1, 2024

Associated Project

Assessing the Potential for Densification and Reduction of Vehicle Miles Traveled in Areas Without Rail

Author(s)

Jae Hong Kim, Nicholas Marantz, Doug Houston, Alex Okashita, Maxwell Cabello

Areas of Expertise

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

View research report

Abstract

While transportation infrastructure and efficiency should inform where to build more housing, little is known about how housing allocation and development processes can be coordinated more systematically with transportation. To date, transportation-housing coordination has often relied on the densification of areas near rail transit stations, putting heavy burdens on these locations and their residents. Much less attention has been paid to how densification can be achieved in a more equitable manner by encompassing other sites.

This report directs attention to non-rail locations, specifically low vehicle miles traveled (VMT) areas and bus corridors, and examines the challenges that can arise in promoting densification more broadly. It shows that data uncertainties can make it challenging to identify low VMT locations and that prioritizing only low VMT locations for residential development may have limited effectiveness in expanding housing opportunities in high opportunity areas. The report further explores ways to achieve more inclusive densification of non-rail transit areas and highlights the importance of anti-displacement strategies.

Related Publications

policy brief | September 1, 2024

What Challenges Can Arise from Coordinating Housing Development with Transportation?

policy brief

Did COVID-19 Fundamentally Reshape Telecommuting in California?

Publication Date

August 1, 2024

Associated Project

Telework Trends in California: Before, During, and Possibly After the Pandemic

Author(s)

Md Rabiul Islam, Jean-Daniel Saphores

Areas of Expertise

Travel Behavior, Land Use, & the Built Environment

View policy brief

Abstract

Health concerns and government restrictions during the COVID-19 pandemic caused a sharp increase in telecommuting (i.e., doing paid work at home or possibly an alternate worksite). In addition to reducing vehicle miles traveled (VMT), decreasing energy use, and lowering emissions of air pollutants and greenhouse gases (GHG), telecommuting may offer numerous other co-benefits, including increasing the worker pool, decreasing time and costs associated with travel, improving work-life balance, and decreasing stress. It may also stimulate greater use of non-motorized and active modes of travel (e.g., walking, biking, taking transit). However, telecommuting (especially during the pandemic) may also affect remote workers’ opportunities for promotion and ties with colleagues, health, work-life balance for families with children (childcare and schools did not operate normally during the pandemic), and even work productivity. It may also increase commuting length because telecommuters tend to live in more suburban areas, usually associated with fewer transit options and a higher likelihood of car use. While a large body of literature on telecommuting existed before COVID-191, this research looked at how the frequency of telecommuting changed in California during the pandemic, and how it may evolve. Whereas most previous research relied on non-random samples, the dataset used for this research was collected at the end of May 2021 by Ipsos, which randomly sampled Californian members of KnowledgePanel©, is the largest probability-based online panel in the nation, so the results are generalizable to California’s population. Quantifying changes in telecommuting is important for updating sustainable community strategies created by Metropolitan Transportation Organizations and gauging telecommuting’s likely contribution to meeting California’s GHG reduction targets. Moreover, analyzing telecommuting frequency for different socio-economic groups and occupations should help policymakers understand the long-term impacts of the pandemic on different segments of the labor market.

Related Publications

published journal article | September 25, 2023

Will COVID-19 Jump-Start Telecommuting? Evidence from California

policy brief

Grocery Shopping in California and COVID-19: Transportation, Environmental Justice, and Policy Implications

Publication Date

August 1, 2024

Associated Project

COVID-19, Commuting, and E-Shopping: Understanding Current and Future Impacts in California

Author(s)

Jean-Daniel Saphores, Lu Xu

Areas of Expertise

Freight, Logistics, & Supply Chain Travel Behavior, Land Use, & the Built Environment

View policy brief

Abstract

The COVID-19 pandemic upended many aspects of our lives, including how we shop for groceries. As grocery stores scaled back their opening hours and managed access, many shoppers switched to online shopping with home delivery (“e-grocery”) or store pick-up (“click-and-pick”). Few empirical studies published to date have explored how the COVID-19 pandemic changed grocery shopping, the extent to which these changes may last, how the pandemic exacerbated grocery store access inequalities, and how access to groceries in California is intertwined with environmental justice concerns. Moreover, most studies on this topic were based on non-random samples, which can provide quick results in a fast-changing environment but their findings are not generalizable.

This brief explores the effects of changing grocery shopping trends on disadvantaged communities in California. Using data obtained by surveying California members of KnowledgePanel,® the largest and oldest online probability-based panel representative of the U.S. population, the research team explored the frequency of grocery shopping in California and likelihood of it changing after the pandemic; the types of stores Californians shopped in for groceries during the pandemic and who used grocery delivery companies; and how / if environmental justice factors played a role in observed changes in grocery shopping.

Related Publications

published journal article | November 18, 2022

Grocery shopping in California and COVID-19: Transportation, environmental justice, and policy implications

working paper

A Comparison of Time-use for Telecommuters, Potential Telecommuters, and Commuters during the COVID-19 Pandemic

Publication Date

July 10, 2024

Associated Project

Connecting Telework, Travel Behavior, and System Performance During the COVID-19 Pandemic

Author(s)

Rezwana Rafiq, Michael McNally

Areas of Expertise

Travel Behavior, Land Use, & the Built Environment

View working paper

Abstract

Throughout the ongoing COVID-19 pandemic, changes in daily activity-travel routines and time-use behavior, including the widespread adoption of telecommuting, have been manifold. This study considers how telecommuters have responded to the changes in activity-travel scheduling and time allocation. In particular, we consider how workers utilized time during the pandemic by comparing workers who telecommuted with workers who continued to commute. Commuters were segmented into those who worked in telecommutable jobs (potential telecommuters) and those who did not (commuters). Our empirical analysis suggested that telecommuters exhibited distinct activity participation and time use patterns from the commuter groups. It also supported the basic hypothesis that telecommuters were more engaged with in-home versus out-of-home activity compared to potential telecommuters and commuters. In terms of activity time-use, telecommuters spent less time on work activity but more time on caring for household members, household chores, eating, socializing and recreation activities than their counterparts. During weekdays, a majority of telecommuters did not travel and in general this group made fewer trips per day compared to the other two groups. Compared to telecommuters, potential telecommuters made more trips on both weekdays and weekends while non-telecommutable workers made more trips only on weekdays. The findings of this study provide initial insights on time-use and the associated activity-travel behavior of both telecommuter and commuter groups during the pandemic.

Related Publications

journal article preprint | January 15, 2024

A Comparison of Time-use for Telecommuters, Potential Telecommuters, and Commuters during the COVID-19 Pandemic

policy brief

Perceptions of Neighborhood Change in a Latinx Transit Corridor

Publication Date

July 1, 2024

Associated Project

Social Impacts of Transit Oriented Development on Disadvantaged Communities

Author(s)

Doug Houston, Michelle Zuniga

Areas of Expertise

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

View policy brief

Abstract

Understanding how residents feel about neighborhood changes due to new development along transit corridors (often referred to as transit-oriented development) remains understudied despite growing concerns over displacement and gentrification. Studies that examined these concerns are largely based on analyzing land use, housing values, and socio-economic shifts (i.e., who is moving in and out of neighborhoods), and do not provide conclusive evidence that transit-oriented development (TOD) is linked to neighborhood gentrification and displacement. Prior surveys of residents living near transit indicate a generally positive assessment of TOD in terms of improved walkability and accessibility but also express concerns over pedestrian safety and parking related to increased traffic and new commercial development. However, recent studies counter this relatively positive assessment of TOD, particularly among activists and community organizers in low-income communities of color.

Related Publications

published journal article | March 22, 2024

The Promise and Pitfalls of Early Project Notification Meetings: Illuminating Santa Ana’s Sunshine Ordinance

published journal article | May 20, 2021

Perceptions of Neighborhood Change in a Latinx Transit Corridor

published journal article

The Promise and Pitfalls of Early Project Notification Meetings: Illuminating Santa Ana’s Sunshine Ordinance

Publication Date

March 22, 2024

Associated Project

Social Impacts of Transit Oriented Development on Disadvantaged Communities

Author(s)

Doug Houston, Michelle Zuniga

Areas of Expertise

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

View published journal article

Abstract

Despite the promise that early public participation could enhance transparency and information access, little is known about which public engagement processes and techniques are most effective at the initial stages of plan development and whether development notification meetings enhance inclusion for impacted residents. Responding to these uncertainties, we analyzed the promise and potential pitfalls of early public notification meetings by reviewing posted development information and interviewing resident leaders and planners involved in the City of Santa Ana’s Sunshine Ordinance development notification meetings for proposed residential and mixed-use projects. Findings confirmed early notification increased access to information and created a more transparent process, but indicated the lack of inclusive practices generated community distrust and opposition and spurred residents to take insurgent actions when meetings offered few specifics and limited collaboration. Findings inform efforts of local jurisdictions and advocates seeking to establish or improve early participation initiatives.

Related Publications

policy brief | July 1, 2024

Perceptions of Neighborhood Change in a Latinx Transit Corridor

published journal article | May 20, 2021

Perceptions of Neighborhood Change in a Latinx Transit Corridor

Phd Dissertation

Exploring Delivery Services Substituting Household Shopping Trips: Implications for Travel, Transportation Networks, and Fleet Optimization, and Insights on the Potential of Autonomous Vehicles

Publication Date

March 12, 2024

Author(s)

Marjan Mosslemi

Areas of Expertise

Travel Behavior, Land Use, & the Built Environment

View Phd Dissertation

Abstract

This dissertation delves into the intersection of two critical elements shaping the future of transportation: opportunities and the challenges presented by shopping delivery services, particularly same-day delivery (SDD), and the necessity to anticipate and explore the forthcoming transportation paradigm with the new possibilities offered by Autonomous Vehicles (AVs). This study investigates the transformative potential of SDD services facilitated by a fleet of shared autonomous vehicles (SAVs) to reshape daily shopping trips and activities.With a dual focus on both the network and household layers, the dissertation addresses the viability of SDD services, considering vehicle miles traveled (VMT) savings and operational strategies for efficient fleet management on one side, and the impacts on travel patterns on the other. Leveraging real-world data for the network of Irvine, CA, and employing optimization methodologies, this dissertation (i) investigates the potential VMT savings from SDD compared to the base scenario where households conduct their own shopping activities, (ii) analyzes the optimal fleet size needed to achieve significant VMT reductions, and (iii) evaluates operational strategies for cost-effective and efficient service delivery. In this dissertation, I analyze the optimal fleet size and system design settings needed to achieve significant VMT reductions without losing profitability and I evaluate operational strategies for cost-effective and time-sensitive service delivery.At the network layer, the system is modeled as a multi-Vehicle and Multi-Depot Pickup and Delivery Problem with Time Windows (m-MDPDPTW), which was implemented in Google OR-Tools. The depots are assumed to be at the warehouse locations from where shopping goods deliveries are made. An analysis is presented for a delivery service comprising an AV fleet serving households on their daily shopping trips for the case study of the City of Irvine, CA. The results indicate these services can significantly decrease the distance traveled and the time spent for shopping trips. The dissertation tests several scenarios to determine how varying possible service operation parameters as well as demand characteristics would affect the results. Scenarios involving varying percentage of the service demand, time window for deliveries, loading/unloading time, and warehouse distribution are considered.At the household layer, the dissertation examines how the SDD service influences household travel patterns and savings, using output from the California Statewide Travel Demand Model (CSTDM) for the City of Irvine. The time saved is used as an accessibility measure. Using the Household Activity Travel Pattern Problem (HAPP), formulated as a pickup and delivery problem with time windows for household daily activities, time saved is compared over four distinct scenarios: a base (existing) case with CSTDM patterns, the HAPP-optimized version of the base case, the base case excluding shopping trips, and its HAPP-optimized version. HAPP-based analysis sheds light on new opportunities in travel and activity planning enabled by AVs as well as insights into future activity patterns shaped by subscription services that may lead to more optimized travel patterns. High Performance Computing is used to tackle the NP-Hard computational problem involved in HAPP in the real-world case study with a large set of households.This research is also intended to establish the viability of operationalizing a HAPP-methodology for analyzing realistic travel network contexts, for transportation policies that involve innovative vehicle usage and routing patterns. A HAPP solution is not a model for the actual household-level travel behavior, but rather a constraint-driven optimal version of it. Nonetheless, with the availability of rich individual level activity data now and in the future, HAPP can indeed become an optimizer for households, if computational problems can be surmounted. This dissertation establishes that computational problems are not insurmountable with current cloud and advanced computing options, even for 4-member households with activities substitutable across individuals, which past research had generally avoided. The research illustrated that, for a real-world network that has an individual and household-level activity-based planning model, or at least a synthesized model of that kind, policy analysis for future transportation options can be done using HAPP to find an optimized implementation of the policy when the behavioral response to such policy is not available in the existing activity models or data. The dissertation also points to future research possibilities involving faster optimizations that can be achieved if HAPP can be implemented with starting feasible solutions that may be developed from existing networks.

policy brief

What Does the Prevalence of Telecommuting Mean for Urban Planning?

Publication Date

January 6, 2024

Associated Project

Telecommuting and the Open Future

Author(s)

Alex Okashita, Jae Hong Kim

Areas of Expertise

Travel Behavior, Land Use, & the Built Environment

View policy brief

Abstract

Researchers at the University of California, Irvine, are looking into what may become the “new normal” in work and work-related travel and the consequences that could have on traffic conditions, efforts to address climate change, and the future of our urban areas, as well as our daily lives. They find, for instance, that current research is largely equivocal about the consequences of telecommuting on where individuals choose to live, their day-to-day travel, and urban/metropolitan development. Equally unclear is how increased telecommuting may impact efforts to create more sustainable and inclusive communities. In light of this uncertainty, they suggest planners and researchers need to pay more attention to the changing nature of urban commuting and how it can play an important role in shaping a more desirable future.

Related Publications

research report | January 6, 2024

Telecommuting and the Open Future

research report

Telecommuting and the Open Future

Publication Date

January 6, 2024

Associated Project

Telecommuting and the Open Future

Author(s)

Alex Okashita, Jae Hong Kim

Areas of Expertise

Travel Behavior, Land Use, & the Built Environment

View research report

Abstract

The COVID-19 pandemic has generated renewed interest in how telecommuting can alter the workings of cities and regions, but there is little guidance on how to align planning practice with the new reality. This report synthesizes the research on telecommuting and its consequences to help planners better understand what effects may occur from the proliferation of telecommuting and what lessons can be drawn from research findings. Emphasis is on the broad relevance of telecommuting to many domains of planning, including housing, land use, community development, and inclusive place-making, while attention is paid to changes in travel demand, vehicle miles traveled (VMT), and greenhouse gas emissions. The research suggests that telecommuting can occur in a variety of ways, and its impacts are largely dependent not only on the type/schedule of telecommuting but also on the built environment, transit accessibility, and other amenities/opportunities the location provides. The varying impacts reported in the research can be seen as an encouragement for planners to actively create a better future rather than merely responding to the rise of telecommuting. Given the breadth of telecommuting’s impacts, systematic coordination across various planning domains will be increasingly important. This report also calls for collaboration across cities to guide the ongoing transformation induced by telecommuting not in a way that leads to more residential segregation but in a way that provides more sustainable and inclusive communities.

Related Publications

policy brief | January 6, 2024