policy brief

Advancing Community-Identified Strategies to Transform Roadways in California’s San Joaquin Valley

Abstract

Disparities in exposure to roadway hazards (e.g., pollution, noise) remain stubbornly persistent due to structural inequalities embedded in the built environment. Research has consistently documented racial/ethnic and socioeconomic disparities in traffic exposures nationwide, including heightened exposure to heavy-duty truck traffic, a significant source of noise and pollution. Such disparities also exist in the provision of sidewalks, bike lanes, and street trees, which can help mitigate roadway dust, noise, and pollution and can increase pedestrian safety, encourage walking and cycling, and provide health benefits.

This publication describes how the research team evaluated opportunities and barriers to using a community steering committee process approach to advance environmental justice and transportation equity. Through interviews and case study analysis, the team examined the role community leaders played in the prioritization and implementation of three community-identified strategies that mitigate roadway hazards in three AB 617 communities in California’s San Joaquin Valley – Stockton, South Central Fresno, and Arvin/Lamont. These strategies include (1) vegetative barriers between roadways and sensitive land uses; (2) expanded sidewalk infrastructure; and (3) revised heavy duty truck route designations.

research report

Between the Forest and the Trees: Community Strategies to Transform Roadways in California’s San Joaquin Valley

Abstract

Expanding participation of historically disenfranchised groups within decision-making processes is an important strategy to increase equity within transportation planning but traditional engagement practices (e.g., public meetings, focus groups) have historically done little to address the needs of disadvantaged communities. This study evaluates the opportunities and barriers to using a community steering committee participation model within transportation planning to advance equity and environmental justice. It utilizes interview and case study analysis to examine the experiences of residents and community leaders in prioritizing community-identified strategies to mitigate roadway hazards in three AB 617 communities in California’s San Joaquin Valley – Stockton, South Central Fresno, and Arvin/Lamont. It investigates the role resident and CBO members played in the prioritization, approval, and implementation of three strategies to transform roadways and mitigate air pollution, noise, dust, and safety hazards: (1) new vegetative barriers between major roadways and sensitive land uses; (2) expanded sidewalk infrastructure; and (3) revised heavy-duty truck route designations. Findings demonstrate that “meaningful involvement” for impacted communities within transportation planning will require officials, residents, and organizations to commit to an ongoing process of experimentation and learning about the most effective approaches for advancing transportation equity and environmental justice.

The Personal Travel Assistant (PTA): Measuring the Dynamics of Human Travel Behavior

Status

Complete

Project Timeline

September 1, 2007 - July 31, 2009

Principal Investigator

Project Team

Rina Dechter, Jee Eun (Jamie) Kang, Craig Rindt, Tuan Nguyen, Yosuke Arai

Department(s)

Civil and Environmental Engineering, Information and Computer Science

Temporal Considerations in Demand Input for Transportation Planning, Analysis, and Simulation

Status

Complete

Project Timeline

April 1, 2008 - July 31, 2009

Principal Investigator

Project Team

Department(s)

Transportation Science Interdisciplinary Graduate Degree Program

Transportation and the Environment: Essays on Technology, Infrastructure, and Policy

Status

Complete

Project Timeline

April 1, 2008 - July 31, 2009

Principal Investigator

Project Team

Project Summary

As emissions from millions of vehicles increase substantially every year, air quality is currently a major problem in California and it seems increasingly difficult to find effective solutions.  These three independent yet related projects attempt to propose possible solutions to deal with California’s air pollution problem.  The first project will evaluate and analyze the increasing interest for hybrid cars in California by quantifying the short term impacts of concerns for air pollution, energy efficiency policies, allowing single-occupant hybrid vehicle to use high-occupancy vehicle  (HOV) lanes in terms of availability, and long term impacts for air pollution and global warming.  The second project attempts to analyze social and environmental impacts of pollution from freight train traffic from/to Southern California ports through Alameda Corridor.  
 The final project revises the work by Giuliano, Hwang and Wachs on the performance of Employee Trip Reduction Program (Rule 2202) in Southern California.  This project will review, evaluate, and analyze the program with is part of Transportation Demand Management (TDM) for improving air quality and traffic congestion and making policy recommendations.

Investigating the Impacts of Smart Charging on Electric Vehicle Charging Choices Within an Activity-based Framework

Status

In Progress

Project Timeline

January 1, 2026 - December 31, 2026

Principal Investigator

Project Team

Department(s)

Civil and Environmental Engineering

Project Summary

The objective of this project is to forecast the impacts of spatio-temporal electricity pricing on electric vehicle (EV) charging behavior, drawing on established EV charging models and incorporating considerations such as smart charging acceptance and joint charging-activity time planning decisions. We aim to elucidate how current and future electricity rates may influence EV driver behavior, while accounting for heterogeneity in charging preferences and value of travel time. Using the Los Angeles metropolitan area as a case study, we develop future year scenarios for EV adoption and charging infrastructure access to evaluate the effects of pricing strategies on the demand for public infrastructure and EV-related trips. Our analysis encompasses a range of smart charging policies, including spatially and temporally-varying electricity prices linked to factors such as charging speeds, utility control, location, and enrollment in bill assistance programs. Results, segmented by travel characteristics such as household income, home charger access,and EV range will quantify the impact of EV charging prices on both aggregate and disaggregate network metrics (e.g., vehicle miles traveled and charging cost savings, respectively.) The results provide insights into the broader implications of electricity pricing strategies for EV integration within the transportation network. The findings of this project are expected to contribute to a deeper understanding of EV charging behavior and access and inform the development of effective demand management strategies within the evolving landscape of transportation electrification.

Phd Dissertation

Sacred placemaking and urban policy the case of Tepoztlán, Mexico

Publication Date

June 30, 2020

Author(s)

Abstract

Sacred places – ranging from religious to secular structures, human created or natural areas, or places with ritual, symbolic, or cultural significance – are rarely addressed by urban planners but are sources of great meaning for many communities. One reason for this neglect is the inherent difficulty in measuring the value and meaning of place for different individuals or groups. This research focused on this challenge by using ethnographic field research methods to gain an in-depth understanding of how people view and interact with sacred places in their community. The case study site of Tepoztlán is an urbanizing pueblo in central Mexico where sacred places play a significant role in daily life, rituals, and festivals and urban forms facilitate these interactions. I asked how sacred meaning was ascribed to places in Tepoztlán, how the built environment impacted behavior around these spaces, how communities preserved sacred places, and the impacts of urbanization on preservation efforts. Findings derived from 53 interviews and three months of field observations revealed five themes characteristic of sacred placemaking in Tepoztlán, including intricate patterns of neighborhood exchange, intergenerational beliefs in sacred mountains, collectivism, pedestrian oriented design, and community involvement in construction of the built environment. Indigenous placemaking is then contrasted with two top-down urban development policies that changed the character of the town and threatened sacred places and placemaking. A tourism program called Pueblos Mágicos [Magical Towns] and expansion of the Pera-Cuautla freeway have degraded and commodified sacred sites and perpetuated unequal distribution of development benefits. The research discusses how employing different views of people-environment interactions beyond dominant Western views can help planners to better understand and plan for preservation of meaningful spaces and in turn preserve and enhance community identity, culture, and self-sufficiency. 

SCC: Community-Centered Optimization of Infrastructure Upgrades and Policy Options for Shared Mobility and Connected Automated Vehicles

Status

In Progress

Project Timeline

October 1, 2021 - September 30, 2026

Principal Investigator

Department(s)

Civil and Environmental Engineering, Transportation Science Interdisciplinary Graduate Degree Program, Urban Planning and Public Policy

Project Summary

We aim to address two societal problems and two interrelated technology challenges facing metropolitan  planning organizations (MPOs). The first societal problem relates to the private-sector’s deployment of  mobility services (e.g. ridesourcing, ridesharing, bikesharing) and connected automated vehicles (CAVs).  Under the right conditions – determining these conditions is a subproblem we will address – mobility service  providers (MSPs) and CAVs can provide significant value to communities in terms of sustainability, livability,  accessibility, mobility (SLAM) and safety [1]. Unfortunately, the financial outlook of MSPs is quite worrisome with both Uber and Lyft losing billions of dollars annually despite (or maybe because of) steady increases  in ridership [2]. Their rapid growth has significantly altered transport systems and life in urban areas,  contributing to increases in traffic congestion [3], [4]. Moreover, the deployment of CAVs is significantly  behind the timeline suggested by manufacturers just a few years ago, delaying the potential community  SLAM benefits of this technology  
The second societal problem relates to the public-sector’s role in the deployment pathways of CAVs and  MSP service options. The concern is that the public-sector will not be proactive in terms of CAV-related  infrastructure investments and MSP- and CAV-related transport policies. If the public-sector only reactively  responds to the requests of private-sector MSPs and CAV developers or other non-community entities, this  may lead to negative societal outcomes (increased congestion, decreased accessibility for the mobility disadvantaged, increased emissions) and the missed opportunity for positive SLAM outcomes in the short and long-term.  
To proactively craft policies and make infrastructure upgrades to address these societal problems, MPOs  need to be able to (1) assess the impacts of infrastructure investments and transport policies on the  transport system, and (2) determine the best CAV-related infrastructure upgrades to improve community  SLAM outcomes. Unfortunately, MPOs in the United States currently lack both sets of these capabilities.  
The first technological challenge facing MPOs is that their regional transport modeling tools were not built  to capture the behavior of MSPs (e.g. Uber and Lyft) nor CAVs, meaning they cannot assess the effects of  transport policies and infrastructure investments on MSPs and CAVs. Hence, we plan to develop models  for MPOs that explicitly capture MSPs and CAVs within the transport system and are sensitive to transport policies and infrastructure investments. Our models will capture the behavioral responses of travelers and  MSPs and network performance impacts of policies and infrastructure investments.  
The second technological challenge facing MPOs is that even within their existing modeling suite, they can  only analyze the impacts of infrastructure investments; they do not have models and algorithms to optimize  infrastructure investments; they can only test different pre-defined infrastructure investments and transport  policies. We plan to develop a bi-level network optimization model and solution algorithms to optimize CAV related infrastructure upgrades. The objective function will include community SLAM metrics. The problem  formulation will also include budgetary constraints and network equilibrium constraints wherein the latter  constraints capture the responses of MSPs and individual travelers to infrastructure upgrades.