policy brief

Decline of Rail Transit Requires New Strategies

Abstract

During the pandemic, California’s four major rail systems— Bay Area Rapid Transit (BART), San Diego Metropolitan Transit System (MTS), Sacramento Regional Transit (SacRT), and Los Angeles County Metropolitan Transportation Authority (LA Metro)—experienced an average ridership decline of 72 percent between 2019 and 2021. BART had the greatest decrease (87 percent) and MTS the lowest (47 percent). However, ridership changes varied significantly across individual stations, with stations located in the central business district or at the end of lines having the highest ridership losses. Land use, development density, and the pedestrian environment are strongly associated with station-level transit ridership. This brief examines how these characteristics affect transit ridership pre- and post-COVID and how they differ across station types based on longitudinal data collected between 2019 and 2021 for 242 rail stations belonging to BART, MTS, SacRT, and LA Metro.

Suggested Citation
Daniel Rodriguez, Susan Pike, Michael McNally and Meiqing Li (2024) Decline of Rail Transit Requires New Strategies. Policy Brief. UC ITS. Available at: https://doi.org/10.7922/g2v986d2.

published journal article

On the stability of user equilibria in static transportation networks

Transportmetrica

Publication Date

January 1, 2008

Author(s)

Suggested Citation
Wen-Long Jin (2008) “On the stability of user equilibria in static transportation networks”, Transportmetrica, 4(1), pp. 1–17. Available at: 10.1080/18128600808685677.

published journal article

Effect of taxi information system on efficiency and quality of taxi services

Transportation Research Record

Publication Date

January 1, 2005

Abstract

In many major metropolitan areas, taxi services have played an important role as a semipublic transportation mode without public support. However, there has not been much modeling effortâ??despite the importance of taxis in urban transportation systemsâ??mainly because of the difficulty in modeling taxi driversâ?? behavior. This study models a taxi service system in urban areas, taking into account taxi driversâ?? knowledge of the transportation network built from their day-to-day experience. Passenger-seeking behavior by taxi drivers is modeled on the basis of their expected travel time and expected waiting time. The model considers the stochastic and dynamic transportation network and various levels of network knowledge on the part of drivers. This modeling approach provides flexibility in modeling the characteristics of taxi operation as well as understanding how taxi driversâ?? capability evolves. The study analyzes the fleet size of taxi service systems and the effects of the taxi companyâ??s information systems by considering quality and operational efficiency of taxi services, from both the passengersâ?? and taxi operatorsâ?? points of view. A simulation experiment shows that the taxi information system can provide benefits equivalent to increasing the number of taxis by 20% in regard to the quality of taxi service.

Suggested Citation
Hyunmyung Kim, Jun-Seok Oh and R. Jayakrishnan (2005) “Effect of taxi information system on efficiency and quality of taxi services”, Transportation Research Record, 1903(1), pp. 96–104. Available at: 10.1177/0361198105190300111.

published journal article

Population and Employment Densities: Structure and Change

Journal of Urban Economics

Publication Date

November 1, 1994
Suggested Citation
Kenneth A. Small and Shunfeng Song (1994) “Population and Employment Densities: Structure and Change”, Journal of Urban Economics, 36(3), pp. 292–313. Available at: 10.1006/juec.1994.1037.

published journal article

Locally charged: Energy justice outcomes of a low-income community solar project in Michigan

Energy Research & Social Science

Publication Date

July 1, 2024

Author(s)

Karl W. Hoesch, Douglas L. Bessette, Dominic Bednar

Abstract

The global transition from fossil fuels to renewable energy has potential to mitigate or exacerbate injustices in the current energy system. Barriers to solar adoption can prohibit low-to-moderate income (LMI) households from realizing the financial benefits of ownership. At the same time, these households are more exposed to cost increases due to aging grid infrastructure and increased demand due to electrification. Procedural injustices mount when those renewables are sited without involving residents in decision-making. Community solar, which allows multiple owners or subscribers to benefit from a single solar array, is considered one solution to these distributional and procedural justice challenges because of its potential to localize energy benefits and decision-making. However, community solar projects and their outcomes vary widely. This study explores one community solar project in a rural community in the upper peninsula of the U.S. state of Michigan. The project contained a carve-out for LMI households identified through participation in the National Weatherization Program (WAP). Through nine semi-structured interviews, 44 phone surveys, and analysis of two years of monthly energy consumption and bill data we sought to understand three energy justice impacts on the targeted community and participants’ perceptions of the program and its processes. We show that positive distributional, procedural, and recognition justice outcomes from community solar are achievable in a context without supportive legislation, under certain conditions. These results may have implications for expanding community solar to LMI households in small towns both in the United States and abroad.

Suggested Citation
Karl W. Hoesch, Douglas L. Bessette and Dominic J. Bednar (2024) “Locally charged: Energy justice outcomes of a low-income community solar project in Michigan”, Energy Research & Social Science, 113, p. 103569. Available at: 10.1016/j.erss.2024.103569.

MS Thesis

Analysis of the 2000 SCAG Post-Census Regional Travel Survey and the 2012 California Household Travel Survey

Publication Date

December 31, 2015

Abstract

Results from the 2000 SCAG Post-Census Regional Travel Survey and the 2010-2012 California Household Travel Survey are used to study the demographics and characteristics of Imperial, Los Angeles, Orange, Riverside, San Bernardino, and Ventura counties. Graphs for each county are created to show pertinent data to transportation applications, such as the average number of vehicles a household owns or how many trips certain individuals make in one day. Studying both sets of data gives perspective on how the SCAG region has evolved over 12 years. The overwhelming majority of trips are still traveled by personal vehicle, despite walking trips seeing an increase over 2000, and trips are more frequent overall.

Suggested Citation
Andrew Timothy (2015) Analysis of the 2000 SCAG Post-Census Regional Travel Survey and the 2012 California Household Travel Survey. MS Thesis. UC Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/u4evf/cdi_proquest_journals_1772381528.

published journal article

Modeling network traffic for planning applications in a small community

Journal of Urban Planning and Development

Publication Date

September 1, 2006

Author(s)

Ming-Sheng Lee, Anthony Chen, Piya Chootinan, Walter Laabs, Will Recker
Suggested Citation
Ming S. Lee, Anthony Chen, Piya Chootinan, Walter Laabs and Will Recker (2006) “Modeling network traffic for planning applications in a small community”, Journal of Urban Planning and Development, 132(3), pp. 156–159. Available at: 10.1061/(asce)0733-9488(2006)132:3(156).

conference paper

Cross-domain security of cyber-physical systems

2017 22nd asia and south pacific design automation conference (ASP-DAC)

Publication Date

January 1, 2017

Author(s)

Sujit Rokka Chhetri, Jiang Wan, Mohammad Al Faruque
Suggested Citation
Sujit Rokka Chhetri, Jiang Wan and Mohammad Abdullah Al Faruque (2017) “Cross-domain security of cyber-physical systems”, in 2017 22nd asia and south pacific design automation conference (ASP-DAC). IEEE, pp. 200–205. Available at: 10.1109/aspdac.2017.7858320.

research report

The effect of organization size and structure on transit performance and employee satisfaction: final report

Suggested Citation
Gordon J. Fielding, Lyman W. Porter, Michael J Spendolini, William D. Todor and Dan R. Dalton (1978) The effect of organization size and structure on transit performance and employee satisfaction: final report. Final Report UMTA-CA-11-0016-79-1. Washington : Springfield, Va.: U.S. Urban Mass Transportation Administration, Office of Policy and Program Development, University Research and Training Division ; Available through the National Technical Information Service. Available at: https://catalog.hathitrust.org/Record/102562469.

conference paper

Play the Imitation Game: Model Extraction Attack against Autonomous Driving Localization

Proceedings of the 38th Annual Computer Security Applications Conference

Publication Date

December 5, 2022

Author(s)

Qijin Zhang, Junjie Shen, Mingtian Tan, Zhe Zhou, Zhou Li, Qi Alfred Chen, Michael Zhang

Abstract

The security of the Autonomous Driving (AD) system has been gaining researchers’ and public’s attention recently. Given that AD companies have invested a huge amount of resources in developing their AD models, e.g., localization models, these models, especially their parameters, are important intellectual property and deserve strong protection. In this work, we examine whether the confidentiality of production-grade Multi-Sensor Fusion (MSF) models, in particular, Error-State Kalman Filter (ESKF), can be stolen from an outside adversary. We propose a new model extraction attack called TaskMaster that can infer the secret ESKF parameters under black-box assumption. In essence, TaskMaster trains a substitutional ESKF model to recover the parameters, by observing the input and output to the targeted AD system. To precisely recover the parameters, we combine a set of techniques, like gradient-based optimization, search-space reduction and multi-stage optimization. The evaluation result on real-world vehicle sensor dataset shows that TaskMaster is practical. For example, with 25 seconds AD sensor data for training, the substitutional ESKF model reaches centimeter-level accuracy, comparing with the ground-truth model.

Suggested Citation
Qifan Zhang, Junjie Shen, Mingtian Tan, Zhe Zhou, Zhou Li, Qi Alfred Chen and Haipeng Zhang (2022) “Play the Imitation Game: Model Extraction Attack against Autonomous Driving Localization”, in Proceedings of the 38th Annual Computer Security Applications Conference. New York, NY, USA: Association for Computing Machinery (ACSAC '22), pp. 56–70. Available at: 10.1145/3564625.3567977.