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

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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

policy brief

How Risky Are Cyber Security Threats Against Autonomous Vehicles?

Publication Date

April 1, 2024

Associated Project

Risk Assessment for Security Threats and Vulnerabilities of Autonomous Vehicles

Author(s)

Qi Alfred Chen

Areas of Expertise

Intelligent Transportation Systems, Emerging Technologies, & Big Data Safety, Public Health, & Mobility Justice

View policy brief

Abstract

To operate safely, autonomous vehicles (AVs) rely on external sensors such as cameras, light detection and ranging (LiDAR) technology, and radar. These sensors pair with machine learning-based perception modules that interpret the surrounding environment and enable the AV to act accordingly. Perception modules are the “eyes and ears” of the vehicle and are vulnerable to cybersecurity attacks. The most critical and practical threats, however, arise from physical attacks that do not require access to the AV’s internal systems. The risks of these types of attacks are still unknown. To advance the field in this area, we conducted the first ever quantitative risk assessment for physical adversarial attacks on AVs. First, we identified relevant attack vectors, or types of cyber security attacks, targeting AV perception modules. Next, we conducted an in-depth analysis of the stages of an attack. Finally, we used these exercises to identify risk metrics and perform a subsequent computation of risk scores for different attack vectors. Through this process, we were able to quantitatively rank the real-life risks posed by different attack vectors identified in existing research. This analysis provides a framework for comprehensive risk analysis to ensure the safety of AVs on our roadways.

Related Publications

research report | April 1, 2024

Risk Assessment for Security Threats and Vulnerabilities of Autonomous Vehicles

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.

Phd Dissertation

Investigation of LiDAR for Traffic Monitoring with emphasis on Heavy Duty Trucks

Publication Date

March 15, 2024

Associated Project

Investigation of LiDAR sensing technology to Improve Traffic Monitoring along Multilane Freeways

Author(s)

Koti Allu

Areas of Expertise

Freight, Logistics, & Supply Chain Intelligent Transportation Systems, Emerging Technologies, & Big Data

View Phd Dissertation

Abstract

Traffic Monitoring is at the center of any Intelligent Transport System. Current traffic monitoring sensors are challenged to deliver in the evolving landscape of connected, autonomous and alternative fuel transportation systems. This dissertation explores the feasibility of emerging LiDAR technology for traffic monitoring, in an infrastructure-based, side-fire LiDAR configuration. LiDAR technology was investigated in terms of providing both the core data elements of existing traffic monitoring systems such as vehicle counts and speeds, as well as more high-resolution data elements required for future connected and autonomous vehicles such as relative positions of vehicles on a roadway, vehicle lateral and longitudinal positions within a lane, physical attributes of individual vehicles, and vehicle microscopic trajectories. LiDAR sensors were deployed at both dense urban corridors and rural highway locations. At the urban location, the LiDAR estimate of vehicle counts across lanes was between 87% to 110% of a baseline calibrated sensor’s vehicle counts. At the rural highway location, microscopic trajectories for vehicles were derived at 0.1 second resolution, enabling detection of anomalies in vehicle behavior. In addition, the precise lateral positions of heavy-duty vehicles were derived at the urban corridor location, with a particular interest being future safety assessment for loss of control of autonomous heavy-duty trucks. The high-resolution traffic data elements derived from this research can assist in detecting anomalous behavior of vehicles, whether from impaired driving or loss of effective autonomous control, with road safety assessments, and in providing inputs for microscopic road emission modeling.

Related Publications

research report | January 30, 2023

Investigation of LiDAR Sensing Technology to Improve Freeway Traffic Monitoring

working paper | August 2, 2021

Vehicle Point Cloud Reconstruction Framework for FHWA axle-based Classification using Roadside LiDAR Sensor

research report

Natural Gas Vehicle Incentive Program

Publication Date

March 1, 2024

Associated Project

California Natural Gas Vehicle Incentive Program

Author(s)

Craig Rindt, Youngeun Bae, Jun Park, Mariana Sebastiani, Esmaeil (Sina) Dabbagh, Stephen Ritchie, Suman Mitra

Areas of Expertise

Freight, Logistics, & Supply Chain Zero-Emission Vehicles & Low-Carbon Fuels

View research report

Abstract

This report presents the results of the Natural Gas Vehicle Incentive Program administered by the Institute of Transportation Studies at the University of California, Irvine under agreement number 600-14-006 with the California Energy Commission. Program development and administration is described, including discussion of outreach efforts and engagement with stakeholders to improve program operations. Performance statistics for the Natural Gas Vehicle Incentive Program are presented describing the characteristics of the 916 vehicles incentivized under the project, and the 87 distinct entities that received incentive funding. Recommendations are offered for future vehicle incentive programs to resolve some of the problems that arose during the administration of the program that were mostly due to structural characteristics of the voucher process itself. The report also details the findings of two major research efforts conducted under the agreement. The first research thrust targeted developing a better understanding of alternative fuel demand from the perspective of fleet operations. This included both fleet purchase behavior as it relates to alternative fuel heavy duty vehicles and also a detailed study of how heavy-duty vehicle operating cycles impact their emissions and suitability for alternative fuel deployments. The second research thrust addressed the implications of scaling specific features of the California Sustainable Freight Action Plan to statewide operations. Using results from the California Statewide Freight Forecasting Model, a case study on optimizing the deployment of overhead catenary electric highway infrastructure around the state in terms of either maximizing vehicle miles traveled coverage or maximizing the accrued benefits to disadvantaged communities.

Related Publications

Phd Dissertation | March 20, 2020

Impacts of electric highways for heavy-duty trucks

Phd Dissertation | September 15, 2019

Environmental Impacts of Various Heavy-Duty Natural Gas Vehicles Incentivized in California

journal article preprint

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

Publication Date

January 15, 2024

Associated Project

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

Author(s)

Rezwana Rafiq, Michael McNally

Areas of Expertise

Infrastructure Delivery, Operations, & Resilience

View journal article preprint

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, the research team considers 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 activities 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

working paper | July 10, 2024

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

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

policy brief

COVID-19 Vaccination Rates Influenced Bus Ridership Recovery

Publication Date

January 1, 2024

Associated Project

Will Transit Ridership Ever Recover From COVID-19? A Case Study of Los Angeles

Author(s)

Henry Bernal, David Brownstone

Areas of Expertise

Public Transit, Shared Mobility, & Active Transportation

View policy brief

Abstract

COVID-19 has had lasting effects on transit ridership, with the worst declines seen in high-income, better educated, urban neighborhoods. However, declines among immigrant and/or low-income households was well documented prior to the pandemic, as more gained access to private vehicles. This has created a unique challenge for transit agencies to bring riders back to transit in cases where they may have already switched to traveling by car or consciously chose to make fewer trips. To better understand ridership during the pandemic, we documented the recovery of bus ridership in Los Angeles County and its relationship with COVID-19 vaccinations between April and December 2021, before the Omicron COVID-19 wave. We then developed a statistical model that relates LA Metro bus ridership as a percentage of October 2019 levels with the percent of adults fully vaccinated by ZIP code. We tested whether the relationship between vaccinations and bus ridership varied by two events: first, the full reopening of businesses in California and second, the wave of COVID transmission caused by the subsequentDelta variant.

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