Digital Commons Network^™

Governing Structures For Successful Regional Transit Coordination And Their Formation, Charles Rivasplata, Richard Lee, Michelle Derobertis, Christopher Ferrell

Mineta Transportation Institute

The expansion of metropolitan areas in California has further prompted the need to improve transportation options for all, more effectively linking origins and destinations through key enhancements to the existing network of transit services. This study provides planners and policymakers examples of effective regional transit coordination agencies. To improve multimodal connections and enhance transit services at the local and regional levels, this study explores regional coordination, focusing on entities charged with coordinating multiple transit agencies in a single metropolitan area. The study identified 16 regional transit coordinators (RTCs), identifying the structure, scope, and management of each. The results revealed that …

Addressing Transportation Construction Workforce Needs Through Innovative Policies And Practices, Thomas O'Brien, Ben Olson, Devin Martinez-Flores

Mineta Transportation Institute

A 2019 survey conducted by the Associated General Contractors of America, prior to the COVID-19 pandemic, found that construction firms across the country are struggling to fill open positions. Eighty percent of survey respondents indicated they have difficulty filling jobs in occupations that are essential to highway construction. This includes heavy equipment operators, cement masons, and iron workers, among others. This workforce shortage in California will become more problematic as public agencies and their contractors seek to implement projects funded by the Bipartisan Infrastructure Law (BIL), also known as the Infrastructure Investment and Jobs Act (IIJA). In California there are …

Assessing Gtfs Accuracy, Gregory L. Newmark

Mineta Transportation Institute

The promised benefits of the General Transit Feed Specification (GTFS) Schedule and Realtime standards are dependent on the underlying quality of the data. Despite this fundamental reliance, there has been relatively little research on techniques and strategies to assess GTFS accuracy. The need for such assessment is growing as federal and state governments increasingly require transit agencies to make these data available to the public. This research fills this gap by presenting a suite of methods and metrics to assess the temporal accuracy of GTFS Realtime and the spatial accuracy of GTFS Schedule feeds. The temporal assessment demonstrates an approach …

Is Parking Cash-Out Worth It? Comparing Cost-Effectiveness And Climate And Equity Benefits In The Bay Area And South Coast Air Quality Management Districts, Fynnwin Prager, Tianjun Lu, Ashley Membere, Parveen Chhetri

Mineta Transportation Institute

This research explores the potential impacts of California parking cash-out policy changes on the Bay Area and LA County. Parking cash-out—a California law since 1992—requires that certain qualifying employers who subsidize employee parking offer employees the option to give up their parking space and receive cash instead. Studies show parking cash-out substantially reduces VMT and emissions, yet enforcement remains voluntary. Current policy covers few firms (<1%) and employees (around 11%) in the study regions. Policy reform to include companies with 20+ employees could increase this to 18%. Our experimental-design survey (n=963) explores behavioral changes in response to multiple policy variables and finds that 76.9% of employees would accept cash-out if offered, and that participants who had to pay the market rate for parking and were full-time commuters were more likely to switch to using public transportation at lower cash minimums. VMT related to employees covered by parking cash-out are substantial (5.6 million in the Bay Area; 5.7 million in LA County), and account for a combined 6,593 daily tons of GHG. As even limited adoption could have significant environmental benefits, parking cash-out would be a more cost-effective approach to reducing VMT than traditional TDM programs such as trip-reduction programs, workplace parking taxation, or transit subsidies and road diets, though further evidence on the direct influence of parking cash-out on commuter behavior is needed.

Time-To-Failure Prediction Of Fine-Grained Soil Slopes Subject To Weather-Driven Deterioration, Arm M. Morsy

Mineta Transportation Institute

Embankments have been widely used in the construction of transportation and flood defense infrastructure. Embankments constructed from clays experience a suite of weather-driven deterioration processes that lead to a progressive loss of hydromechanical performance, causing potentially severe and costly consequences. This study aimed to predict the time to failure of aging, deteriorating clay embankments supporting transportation infrastructure. A multi-phase numerical modeling approach was developed to replicate the long-term, weather-driven, hydromechanical behavior of clay embankments. This model simulated the behavior of a number of well-documented embankment failure case studies that had sufficient data to derive the necessary soil properties and climate …

Ten Years Forward: An Evaluation Of California’S Active Transportation Program, Bruce Appleyard, Mario Carbajal, Madison Swayne, Nell Ahangarfabrik, Megan Honey

Mineta Transportation Institute

California’s Active Transportation Program (ATP) is a competitive, grant-based program that serves as a major funding stream for active transportation infrastructure in California. The program has six goals based on increasing nonmotorized transportation, safety, equity, sustainability, and health. Evaluation of the ATP’s administrative and scoring processes is crucial to ensure goals are met as equitably and efficiently as possible. Additionally, establishing a methodology for evaluating the safety impacts of active transportation projects is critically important. Through a series of interviews and an extensive review of the documents and rubrics of the program, this report discusses how the Active Transportation Program …

Moving Towards The Electrification Of Medium- And Heavy-Duty Vehicles In The Inland Empire, Kimberly Collins, Raffi Der Wartanian, Francisca Beer, Yunfei Hou

Mineta Transportation Institute

This report investigates the transition to zero-emission medium- and heavy-duty vehicles (MDHD) within California’s Inland Empire (IE), emphasizing the significance of electric vehicle charging infrastructure and opportunity charging strategies in facilitating sustainable transportation. Utilizing a mixed-methods approach that combines a systematic literature review, geospatial and big data analytics, and thematic analysis of expert interviews, the study explores the multifaceted challenges and opportunities of electrification. The literature review assesses policies at various governance levels, while geospatial analysis identifies regional traffic patterns and infrastructure needs. Big data analytics examine vehicle movements, complemented by insights from interviews with 16 regional experts, offering a …

Forecasting Commercial Vehicle Miles Traveled (Vmt) In Urban California Areas, Steve Chung, Jaymin Kwon, Yushin Ahn

Mineta Transportation Institute

This study investigates commercial truck vehicle miles traveled (VMT) across six diverse California counties from 2000 to 2020. The counties—Imperial, Los Angeles, Riverside, San Bernardino, San Diego, and San Francisco—represent a broad spectrum of California’s demographics, economies, and landscapes. Using a rich dataset spanning demographics, economics, and pollution variables, we aim to understand the factors influencing commercial VMT. We first visually represent the geographic distribution of the counties, highlighting their unique characteristics. Linear regression models, particularly the least absolute shrinkage and selection operator (LASSO) and elastic net regressions are employed to identify key predictors of total commercial VMT. LASSO regression …

Experimental Investigation Of The Self-Healing Potential Of Bacteria For Sustainable Concrete Structures Phase 2, Andrea Calabrese, Pitiporn Asvapathanagul, Nisarg N. Patel, Nanubala Dhruvan, Austin Adams, Michael Hernandez, Douglas S. Lopez-Cruz

Mineta Transportation Institute

Concrete is a critical component of so much of the modern construction industry. This material, well known for its versatility, robustness, longevity, and strength, is well-suited for a wide range of structural applications. Nonetheless, the widespread occurrence of cracks in concrete structures, primarily attributed to its limited tensile strength, shrinkage, and overstain, imposes a considerable economic and environmental challenge when it comes to retrofitting these fissures. This study tackles this problem by harnessing bacteria tolerant to high alkaline conditions to enable Microbially Induced Calcium Carbonate Precipitation (MICP) for the self-repair of concrete. This is achieved through an external application method, …

Spatio-Temporal Analysis Of The Roadside Transportation-Related Air Quality (Startraq 2022): Data-Driven Exposure Analysis By Transportation Modes, Jaymin Kwon, Yushin Ahn, Steve Chung

Mineta Transportation Institute

Particulate matter (PM) pollution poses significant health risks, influenced by various meteorological factors and seasonal variations. This study investigates the impact of temperature and other meteorological variables on PM10 and PM2.5 levels in Fresno County, known for high air pollution. Multiple linear regression (MLR) and generalized additive models (GAMs) assess the significance of these relationships. Analyzing data from Fresno County, we examine PM10 and PM2.5 levels across "hot" (June to August) and "cool" (September to May) seasons. Findings indicate PM10, both MLR and GAM models identify statistically significant variables, excluding temperature and wind direction in each season. However, during the …

Exploring Performance-Based Contracts: A Good Option To Address Long-Term Road Maintenance In California?, Maria Calahorra-Jimenez, Richard Poythress

Mineta Transportation Institute

Performance-based contracts (PBCs) used in road maintenance provide flexibility for considering new materials, design, and technology to achieve predetermined performance targets. Several states in the U.S. have already used these types of contracts in road maintenance, and their experience can inform the use of PBCs in California. The objectives of this research are twofold. First, identify the benefits and challenges of PBCs compared to traditional contracts. Second, explore the main aspects of PBCs implementation for road maintenance and relate them to California's context. To this end, deductive-inductive content analysis was conducted on 84 peer-reviewed articles published between 1998 and 2023. …

Battery Management System Development For Electric Vehicles And Fast Charging Infrastructure Improvement, Yu Yang, Hen-Geul Yeh, Cesar Ortiz

Mineta Transportation Institute

The electric vehicle (EV) has become increasingly popular due to its being zero-emission. However, a significant challenge faced by EV drivers is the range anxiety associated with battery usage. Addressing this concern, this project develops a more efficient battery management system (BMS) for electric vehicles based on a real-time, state-of-charge (SOC) estimation. The proposed study delivers three modules: (1) a new equivalent circuit model (ECM) for lithium-ion batteries, (2) a new SOC estimator based on the moving horizon method, and (3) an on-board FPGA implementation of the classical Coulomb counting method for SOC estimation. The research team extends the traditional …

Mapping Of Pavement Conditions Using Smartphone/Tablet Lidar Case Study: Sensor Performance Comparison, Calvin Beavers, Chad Day, Austin Krietemeyer, Scott M. Peterson, Yushin Ahn, Xiaojun Li

Mineta Transportation Institute

Poor road conditions affect millions of drivers, and assessing the condition of paved surfaces is a critical step towards repairing them. This project explores the feasibility of using the Apple iPad Pro LiDAR sensor as a cost-effective tool for assessing the damage and condition of paved surfaces. Our research aims to provide accurate and precise measurements using readily available consumer devices and compare the results to state-of-the-art equipment. This investigation involved visual inspection, identification, and classification of pavement distresses, followed by a comparison of the iPad and iPhone LiDAR data with a survey-grade terrestrial laser scanner. The project revealed several …

Smart Robot Design And Implementation To Assist Pedestrian Road Crossing, Hovannes Kulhandjian

Mineta Transportation Institute

This research focuses on designing and developing a smart robot to assist pedestrians with road crossings. Pedestrian safety is a major concern, as highlighted by the high annual rates of fatalities and injuries. In 2020, the United States recorded 6,516 pedestrian fatalities and approximately 55,000 injuries, with children under 16 being especially vulnerable. This project aims to address this need by offering an innovative solution that prioritizes real-time detection and intelligent decision-making at intersections. Unlike existing studies that rely on traffic light infrastructure, our approach accurately identifies both vehicles and pedestrians at intersections, creating a comprehensive safety system. Our strategy …

Examining Transit Service Improvements With Internet-Of-Things (Iot): A Disparity Analysis, Shailesh Chandra, Robert Valencia, Vamsi Krishna Oruganti

Mineta Transportation Institute

Literature shows that poor service reliability of transit often leads to uncertain waiting times at transit stations, diminishing their popularity and usage, and this particularly affects low-income populations more likely to rely heavily on transit. This research delves into an in-depth analysis of the inequality assessment of the Los Angeles (LA) Metro Rail lines, with a particular focus on evaluating the potential impacts of integrating Internet of Things (IoT) technology. This study investigates how IoT could influence service connectivity, accessibility, and the existing disparities in transit services. The primary goal of this study is to assess how the implementation of …

Fresno County Afterschool Transportation Education, Christian Wandeler, Felipe Mercado

Mineta Transportation Institute

Transportation is a critical infrastructure, and K–12 students benefit from understanding the industry and how it impacts their lives. This comprehensive report investigates the landscape of transportation education via the lens of the Madera Unified School District's afterschool programs, thus highlighting its crucial role in shaping the futures of students and, consequently, society. It further explores the substantial enhancements in learning, career readiness, and societal awareness that can be achieved through the strategic incorporation of transportation concepts into K–12 education, augmented by the support of afterschool programs and online educational technologies. The study tackles challenges and explores ways to make …

Exploring Equity Frameworks For A Cross-Jurisdictional Vehicle Miles Traveled Mitigation Program In Santa Clara County, Serena Alexander, Luana Chen, Maxwell Belote-Broussard

Mineta Transportation Institute

The Santa Clara Valley Transportation Authority (VTA) partnered with a Mineta Transportation Institute (MTI) research team and San José State University (SJSU) students for assistance in developing the equity framework for the agency’s proposed Equitable Vehicle Miles Traveled (VMT) Mitigation Program. The goal of the program is to reduce the amount of driving generated from new developments in Santa Clara County through transportation solutions with equity and cross-jurisdictional collaboration in mind. During the Fall 2023 semester, graduate urban planning students from SJSU worked to develop policy recommendations for the program equity framework through a literature review, spatial analysis, community engagement …

Does California High-Speed Rail Promote Accessibility For Station Cities?: Case Study Of Fresno And Merced, Chih-Hao Wang, Na Chen

Mineta Transportation Institute

California High-Speed Rail (CHSR) will largely change transportation cost across the state after it starts operating. Past studies show that only Fresno and Merced among station cities in the Central Valley would attract more future activities with the CHSR. The establishment of active CHSR also implies a new daily living sphere for all the station cities, and, therefore, accessibility to work and residential amenities should be reviewed to inform planners of future land-use and transportation developments. A research framework has been developed better to understand the impact of CHSR on job and amenity accessibility by driving, transit, and walking in …

What Do Americans Think About Federal Tax Options To Support Transportation? Results From Year Fifteen Of A National Survey, Asha Weinstein Agrawal, Hilary Nixon

Mineta Transportation Institute

This report summarizes the results from the fifteenth year of a national public opinion survey asking U.S. adults questions related to their views on federal transportation taxes. A nationally representative sample of 2,522 respondents completed the online survey from February 7 to March 12, 2024. The questions test public opinions about raising the federal gas tax rate, replacing the federal gas tax with a new mileage fee, and imposing a mileage fee just on commercial travel. In addition to asking directly about support for these tax options, the survey collected data on respondents’ views on the quality of their local …

Traffic Sign Extraction From Mobile Lidar Point Cloud, Yushin Ahn, Riadh Munjy, Ziyuan Li

Mineta Transportation Institute

The extraction of traffic signs from Mobile Light Detection and Ranging (LiDAR) point cloud data has become a focal point in transportation research due to the increasing integration of LiDAR technologies. LiDAR, a remote sensing technology, captures detailed three-dimensional point cloud data, offering a comprehensive view of the surrounding environment. Mobile LiDAR systems mounted on vehicles enable efficient data collection, particularly for large-scale road networks. This study aims to develop and refine techniques for extracting traffic signs from Mobile LiDAR point cloud data, essential for enhancing road safety, navigation systems, and intelligent transportation solutions. By leveraging LiDAR technology, new possibilities …

Impervious Surfaces From High Resolution Aerial Imagery: Cities In Fresno County, Yushin Ahn, Richard Poythress

Mineta Transportation Institute

This study investigates impervious surfaces — areas covered by materials with restricted water permeability, such as pavement, sidewalks, and parking lots—due to their crucial role in influencing water dynamics within urban landscapes. The impermeability of these surfaces disrupts natural water absorption processes, resulting in adverse environmental consequences such as increased flooding, erosion, and water pollution. The research employs impervious surface analysis, a method involving the mapping and analysis of these surfaces within specified study areas, including cities, counties, and census tracts. Remote sensing techniques, specifically satellites and aerial imagery, are commonly utilized for the identification and classification of impervious surfaces. …

Transit Workforce Development Challenges And Mitigation Practices, Jodi Godfrey

Mineta Transportation Institute

The objective of this research is to summarize previously conducted research related to workforce development challenges in the transit industry, detailing major findings and subsequent recommendations based on the annotated bibliography of the current atmosphere and most successful ways to mitigate those challenges to attract and retain talent in the transit industry. According to the U.S. Chamber of Commerce, the U.S. had over 10 million job openings and only 5.7 million unemployed workers in March 2023. In 2017, the Washington Post posited that there were not enough workers to fill the vacancies, as the U.S. Census Bureau announced a 17-year …

The Transportation Sector, Cap-And-Trade And Blockchain: A Carbon Credit Trading Platform, Aditya Mankar, Forouzan Golshani

Mineta Transportation Institute

This study offers a solution that facilitates direct trading of carbon credits with no intermediaries by using blockchain technology aligned with the cap-and-trade system. With this solution, along with other major transformations in the industry, the transportation sector can take more ownership of emissions and mitigate the impact of its role as the largest contributor of greenhouse gasses. The solution sits at the confluence of the Cap-and-Trade initiative, carbon credit trading, and blockchain technology. Although the concept of blockchains has been the subject of significant curiosity, scrutiny, boosterism, investment, criticism, it most importantly is at the core of useful, rapidly …

How Will California’S Electric Vehicle Policy Impact State-Generated Transportation Revenues? Projecting Scenarios Through 2040, Asha Weinstein Agrawal, Hannah King, H. A. “Burt” Tasaico

Mineta Transportation Institute

California faces unprecedented uncertainty about how much revenue the state will raise from a package of taxes on motor fuels and annual registration fees on light-duty vehicles that was established in 2017 by Senate Bill 1 (SB 1). The SB 1 taxes are by far the largest source of revenue that the State of California generates to support maintenance, operations, and improvements for state highways, and the funds also contribute substantially to local transportation and public transit budgets. To help policymakers navigate the uncertainty about future SB 1 transportation revenue, this study used spreadsheet models to project revenue from the …

Understanding Workforce Diversity In The Transit Industry: Establishing A Baseline Of Diversity Demographics, Asha W. Agrawal, Evelyn Blumenberg, Anastasia Loukaitou-Sideris, Brittney Lu

Mineta Transportation Institute

This study provides baseline data on the status of the racial/ethnic and gender diversity of the transit agency workforce in the U.S. and identifies potential barriers and promising practices for diversifying this workforce. Public transit agencies function best when the diversity of their workforce represents the communities they serve, yet previous research finds an underrepresentation of women and minorities in senior and managerial roles, along with an overconcentration of men and workers of color—particularly Black workers—in operational roles (e.g., drivers, janitors).

The study updates those earlier studies with newer data drawn from five discrete research tasks: 1) review of the …

Investigating The Effects Of Alcohol Consumption On Manual And Automated Driving: A Systematic Review, Miaomiao Dong, Yuni Lee, Jackie Cha, Gaojian Huang

Mineta Transportation Institute

There are direct correlations between drunk driving and car-related injuries, disabilities, and death. Autonomous vehicles (AVs) may provide useful driver support systems to prevent or reduce road accidents. However, AVs are not yet fully automated and require human drivers to take over the vehicle at times. Therefore, understanding how alcohol affects driving performance in both manual and automated driving is important because manual drives may offer insights into the takeover process in AVs. A systematic review of 53 articles from eight databases was conducted. Findings were categorized based on the human information processing model, which can be extended to the …

Beneath I-280: Excavating A Neighborhood Lost To San José Freeways, Leila Ullmann, Gordon Douglas

Mineta Transportation Institute

Throughout the 1960s and 1970s, thousands of people in San José, California were displaced from their homes as the state used eminent domain to purchase land and uproot neighborhoods for the construction of Interstate freeways. This report presents a multifaceted research and public knowledge effort that uncovers some of the communities buried beneath these freeways, in the area where I-280 and CA-87 meet today near downtown San José. The project builds primarily from previously unprocessed California Department of Transportation (CalTrans) archival documents, which this project studies for the first time. The records are rich in detail about valuation and sale …

A Practical Framework For Component-Level Structural Health Monitoring Of The Gerald Desmond Bridge, Mehran Rahmani, Vesna Terzic, Andrea Calabrese, Brittany Cambell

Mineta Transportation Institute

Bridges serve as critical transportation infrastructure, but traditional maintenance inspection to ensure their safety is time-consuming, costly, and labor-intensive, especially for larger and more complex structures. This study presents a practical framework for the instrumentation, data acquisition, and remote condition assessment of the Gerald Desmond Bridge, California’s largest cable-stayed bridge. The framework aims to establish a foundation for real-time or near real-time remote health monitoring of the bridge’s critical elements. The study highlights the advantages of remote monitoring in terms of efficiency, cost-effectiveness, and early detection of damage.

Learning About Street Harassment On Transit: A Survey Instrument For Transit Agencies, Asha Weinstein Agrawal, Jon Canapary, Carol Anne Caroll, Tam J. Guy, Anastasia Loukaitou-Sideris

Mineta Transportation Institute

This study was conducted in accordance with California Senate Bill 1161 (2022), legislation that directed the Mineta Transportation Institute to develop a reliable, easy-to-use survey instrument for collecting information from public transit passengers about the extent, location, and characteristics of any street harassment they experience. Although the legislation is focused on large California transit agencies, the study findings are equally relevant to smaller agencies and agencies outside the state. To develop the recommended questionnaire, we reviewed literature about street harassment, analyzed transit passenger surveys to explore the questions asked about safety and harassment, received feedback on iterative drafts of the …

Evaluating Benefits From Transportation Investments Aligned With The Climate Action Plan For Transportation Infrastructure (Capti), Serena Alexander, Shams Tanvir, T. William Lester

Mineta Transportation Institute

Building upon two executive orders targeting the mitigation of greenhouse gas (GHG) emissions in California, the Climate Action Plan for Transportation Infrastructure (CAPTI) offers a comprehensive plan to work toward a more unified vision for transportation that prioritizes climate, health, and social equity. The purpose of this project was to help evaluate the benefits from transportation investments across the State of California. With support from Caltrans, the research team provided a holistic evaluation framework that involved an analysis of vehicle miles traveled (VMT) and emissions impacts, an economic impact analysis, and an equity analysis of transportation investments in California. Findings …