Phd Dissertation
Orientation to Work and Grievance Behavior
Publication Date
January 1, 1979
Archives: Research Products
published journal article
Mobility and environment improvement of signalized networks through Vehicle-to-Infrastructure (V2I) communications
Transportation Research Part C: Emerging Technologies
Publication Date
July 1, 2016
Author(s)
Gerard Aguilar Ubiergo, Wenlong Jin
Suggested Citation
Gerard Aguilar Ubiergo and Wen-Long Jin (2016) “Mobility and environment improvement of signalized networks through Vehicle-to-Infrastructure (V2I) communications”, Transportation Research Part C: Emerging Technologies, 68, pp. 70–82. Available at: 10.1016/j.trc.2016.03.010. published journal article
Compound Risk of Air Pollution and Heat Days and the Influence of Wildfire by SES across California, 2018–2020: Implications for Environmental Justice in the Context of Climate Change
Climate
Publication Date
October 1, 2022
Author(s)
Shahir Masri, Yufang Jin, Jun Wu
Abstract
Major wildfires and heatwaves have begun to increase in frequency throughout much of the United States, particularly in western states such as California, causing increased risk to public health. Air pollution is exacerbated by both wildfires and warmer temperatures, thus adding to such risk. With climate change and the continued increase in global average temperatures, the frequency of major wildfires, heat days, and unhealthy air pollution episodes is projected to increase, resulting in the potential for compounding risks. Risks will likely vary by region and may disproportionately impact low-income communities and communities of color. In this study, we processed daily particulate matter (PM) data from over 18,000 low-cost PurpleAir sensors, along with gridMET daily maximum temperature data and government-compiled wildfire perimeter data from 2018–2020 in order to examine the occurrence of compound risk (CR) days (characterized by high temperature and high PM2.5) at the census tract level in California, and to understand how such days have been impacted by the occurrence of wildfires. Using American Community Survey data, we also examined the extent to which CR days were correlated with household income, race/ethnicity, education, and other socioeconomic factors at the census tract level. Results showed census tracts with a higher frequency of CR days to have statistically higher rates of poverty and unemployment, along with high proportions of child residents and households without computers. The frequency of CR days and elevated daily PM2.5 concentrations appeared to be strongly related to the occurrence of nearby wildfires, with over 20% of days with sensor-measured average PM2.5 > 35 μg/m3 showing a wildfire within a 100 km radius and over two-thirds of estimated CR days falling on such days with a nearby wildfire. Findings from this study are important to policymakers and government agencies who preside over the allocation of state resources as well as organizations seeking to empower residents and establish climate resilient communities.
Suggested Citation
Shahir Masri, Yufang Jin and Jun Wu (2022) “Compound Risk of Air Pollution and Heat Days and the Influence of Wildfire by SES across California, 2018–2020: Implications for Environmental Justice in the Context of Climate Change”, Climate, 10(10), p. 145. Available at: 10.3390/cli10100145.
policy brief
Transportation Network Companies Might Be Pulling Riders from Public Transit, but This Could Change
Publication Date
May 1, 2023
Associated Project
Author(s)
Susan Shaheen, Elliot Martin, Adam Stocker
Areas of Expertise
Abstract
Transportation Network Companies (TNCs, also known as ridehailing and ridesourcing) have expanded across California over the past decade and changed the way people travel. Using a smartphone, travelers can quickly summon a vehicle from almost anywhere and know what the estimated wait time, travel time, and cost will be before stepping into the vehicle. While TNCs are clearly addressing an unmet need for travelers, their growing popularity has raised a number of policy questions, including if TNCs are shifting people away from public transit and other travel modes (e.g., carshare, walking, biking).
Suggested Citation
Susan Shaheen, Elliot Martin and Adam Stocker (2023) Transportation Network Companies Might Be Pulling Riders from Public Transit, but This Could Change. Policy Brief. UC ITS. Available at: https://doi.org/10.7922/g2rf5sbh.Related Publications
published journal article |
Jan 2024
What Is the Connection? Understanding Shared Micromobility Links to Rail Public Transit Systems in Major California Cities
Sustainability
working paper
Integrated Construction Zone Traffic Management
Publication Date
June 1, 2008
Author(s)
Abstract
Nonrecurrent traffic congestion caused by construction work constitutes a large proportion of the traffic congestion on highways. In TO 5300, we developed a comprehensive work zone traffic impact assessment procedure using a series of state-of-the-art dynamic network analysis tools as building blocks. This procedure is then implemented into a work zone traffic impact assessment software package called NetZone. This software package is capable of estimating time-dependent travel demand based on link counts, estimating demand diversion in response to work zone delay and various traffic management measures, showing traffic congestion level in the network over time, and providing network wide traffic performance measures with and without traffic congestion mitigation measures. The traffic performance measures provided in NetZone include average and longest delays, average and longest queue lengths, as well as the total delay in the network, before and during construction. Moreover, a friendly graphical userinterface makes NetZone easy to learn and use, and a preliminary case study shows that one canuse it to study a reasonably large network in a fraction of time that a micro-simulation package takes for the same network.
The developed methods and tools can help better plan and operate construction activities on highways, and more effectively manage traffic to reduce travel delays, both are consistent with Caltrans’s goals of increasing productivity and safety.
conference paper
Detecting Data Spoofing in Connected Vehicle based Intelligent Traffic Signal Control using Infrastructure-Side Sensors and Traffic Invariants
2023 IEEE Intelligent Vehicles Symposium (IV)
Publication Date
June 1, 2023
Author(s)
Abstract
Connected Vehicle (CV) technologies are under rapid deployment across the globe and will soon reshape our transportation systems, bringing benefits to mobility, safety, environment, etc. Meanwhile, such technologies also attract attention from cyberattacks. Recent work shows that CV-based Intelligent Traffic Signal Control Systems are vulnerable to data spoofing attacks, which can cause severe congestion effects in intersections. In this work, we explore a general detection strategy for infrastructure-side CV applications by estimating the trustworthiness of CVs based on readily-available infrastructure-side sensors. We implement our detector for the CV-based traffic signal control and evaluate it against two representative congestion attacks. Our evaluation in the industrial-grade traffic simulator shows that the detector can detect attacks with at least 95% true positive rates while keeping false positive rate below 7% and is robust to sensor noises.
Suggested Citation
Junjie Shen, Ziwen Wan, Yunpeng Luo, Yiheng Feng, Z. Morley Mao and Qi Alfred Chen (2023) “Detecting Data Spoofing in Connected Vehicle based Intelligent Traffic Signal Control using Infrastructure-Side Sensors and Traffic Invariants”, in 2023 IEEE Intelligent Vehicles Symposium (IV). 2023 IEEE Intelligent Vehicles Symposium (IV), pp. 1–8. Available at: 10.1109/IV55152.2023.10186689. published journal article
Mitigating climate change through transportation and land use policy: Opportunities and challenges
Environmental Law Reporter
Publication Date
January 1, 2019
Author(s)
Alejandro E. Camacho, Melissa L. Kelly, Nicholas Marantz, Gabriel Weil
Suggested Citation
Alejandro E. Camacho, Melissa L. Kelly, Nicholas J. Marantz and Gabriel Weil (2019) “Mitigating climate change through transportation and land use policy: Opportunities and challenges”, Environmental Law Reporter, 49(5), pp. 10473–10492. Available at: https://www.elr.info/articles/elr-articles/mitigating-climate-change-through-transportation-and-land-use-policy. working paper
Bibliography on Transit Operator Stress and Absenteeism, Workers' Compensation and Extraboards
Publication Date
March 1, 1983
Author(s)
Working Paper
UCI-ITS-WP-83-3
Areas of Expertise
Abstract
This bibliography was prepared as supporting documentation for Project I/BTH-Bl-002 (ITS) conducted by the Institute of Transportation Studies, University of California, Irvine, under the sponsorship of the State of California’s Business, Transportation and Housing Agency. This project reviewed three facets of human resource productivity in public transit: workers’ compensation costs, extraboard scheduling and operator stress. These seemingly disparate topics share a common attribute: they each have been associated with the costs of absenteeism in the transit industry. Management concerns about abuses of workers’ compensation have led them to regard this program as a significant incentive for absenteeism. Extraboards, in contrast, have helped to insure schedule reliability by providing a ready pool of labor to replace absent employees. 1 The phenomenon of operator stress has occupied a middle ground, viewed by some as a cause of workers’ compensation claims, and by others as a result of traditional scheduling practices, such as the extraboard. This bibliography reviews over 50 international studies which have addressed the interrelated issues of absenteeism, workers’ compensation, extraboard scheduling and stress-related illness in the transit industry. Section I provides bibliographic information and summary abstracts of each of these studies. Section II describes two recently initiated U.S. research projects which are exploring transit operator stress, hypertension, and operator performance for the U.S. Department of Transportation and the National Academy of Science’s Transportation Research Board. Section Ill, prepared by project assistants Susan Lesh and Marianne Miasnik, lists a number of general studies of workers’ compensation reviewed as background to our current study.
Suggested Citation
Lyn Long and James L. Perry (1983) Bibliography on Transit Operator Stress and Absenteeism, Workers' Compensation and Extraboards. Working Paper UCI-ITS-WP-83-3. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/46m1j1x1. MS Thesis
A Case Study of Transportation Behavior and Analysis at UC Irvine
Areas of Expertise
Abstract
The purpose of this study is to provide a comprehensive analysis of UC Irvine affiliate transportation patterns and behavior. Through this analysis, recommendations on how to best promote more sustainable transportation on the UC Irvine campus was made to the two study sponsors, UCI Transportation and Distribution Services (TDS) and Anteater Express. With the assistance of TDS, an online survey was sent through a campus-wide email, and achieved overall sample size n = 2,034. Due to technical errors, freshmen did not receive the email. However, through the assistance of UCI Student Housing, surveys were sent to on-campus freshmen. Consequently, this still left out the off-campus freshmen and this exclusion impacted our analysis. Set aside from this limitation, the current study provided a framework, to the study sponsors, for an unprecedented comprehensive campus-wide transportation analysis at UC Irvine based on the study sponsor’s goals and objectives. Results indicate there is room for improving the use of alternative transportation for UCI affiliates who live within the City of Irvine in which UC Irvine is located. One recommendation pertains to increasing awareness of more sustainable transportation option and shedding light on transportation impacts early on such as during incoming student orientation and when students move out of the dorms and into local rental communities. That way when new UCI affiliates attempt to get acclimated to their new surroundings, with the early information, they can get the idea to explore alternative transportation as a potential way to be included within their daily life.
Suggested Citation
Chad Kim (2013) A Case Study of Transportation Behavior and Analysis at UC Irvine. MS Thesis. UC Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/17uq3m8/alma991033451549704701. working paper
A Microsimulation of Daily Activity Patterns
Publication Date
December 1, 2000
Author(s)
Working Paper
UCI-ITS-WP-00-7, UCI-ITS-AS-WP-00-7
Areas of Expertise
Abstract
This paper documents the prototype development, application, and validation of a pattern synthesis model based on activity-travel pattern classifications. The technique proposed is a microsimulation approach to construct daily activity patterns for individuals established on empirical distributions of representative activity patterns and distributions of additional travel characteristics contained by every pattern. The method clearly recognizes the complex, stochastic nature of activity-travel behavior in terms of activity generation, spatial choice, and scheduling components. A successful application of the model is outlined using data from the 1994 Portland Activity Travel Survey.