working paper

Evaluation of a Shared-Use Electric Vehicle Program: Integrating a Web-Based Survey with In-Vehicle Tracking

Publication Date

June 1, 2001

Author(s)

Ming-Sheng Lee, James Marca, Craig Rindt, Angela Koos, Michael McNally

Working Paper

UCI-ITS-WP-01-10, UCI-ITS-AS-WP-01-5

Areas of Expertise

Public Transit, Shared Mobility, & Active Transportation

View working paper

Abstract

An experimental shared-use vehicle program in Irvine, California, is assigning 15 Toyota ecom electric vehicles to several public and private sector organizations who have identified a group of employees to utilize the vehicles in a shared-use mode. The primary goal of this experiment is to evaluate the potential of shared-use electric vehicles as a means of reducing urban traffic and vehicle emissions. The decision to travel with the shared-use vehicles can be understood only through examining the entire process of how participants schedule activites before, during and after shared-use vehicles become a travel option. To effectively evaluate performance of this prototype application, a novel data collection procedure is proposed that integrates GPS-based vehicle tracking and web-based travel survey technologies. The data collection process will occur in three stages: (1) before the vehicle-sharing program, (2) during the program and (3) after the program is completed. A computer-aided self-administered interview (CASI) program, REACT!, is being used to collect travel/activity schedules from participants for one week periods. The data derived from the first stage will depict participants’ typical weekly activity programs before the alternative of sharing vehicles is present. After a simple installation of REACT! on a home or work personal computer, each respondent completes a 45 minute self-administered inverview and summarizes known travel plans for the week. On each subsequent evening, REACT! prompts respondents to update what they actually did that day, as well as to update any plans for the remainder of the week. Data are sent to a project web site at the end of each REACT! session. At the end of the week, REACT! provides a summary of travel/activity for the entire week. In the second phase, when electric vehicles are in shared-use, REACT! will be used in conjunction with the GPS tracing instrument, TRACER, equipped within the study vehicles. TRACER will be used to track each venicle for the duration of the study, recording vehicle position and speed every second. At one of two intervals within the six month study period, respondents will repeat the REACT! study. These repeat applications will involve a brief initial self-administered interview and daily updates focused on the use of the shared-use vehicles. The actual tracings of the vehicles will be provided to each respondent both as a memory-jogger to help them complete the survey as well as to examine under what conditions shared-use vehicles were utilized. In the third stage, the stage 1 procedure will be repeated to test for residual effects on travel patterns.

Suggested Citation

Ming S. Lee, James E. Marca, Craig R. Rindt, Angela M. Koos and Michael G. McNally (2001) Evaluation of a Shared-Use Electric Vehicle Program: Integrating a Web-Based Survey with In-Vehicle Tracking. Working Paper UCI-ITS-WP-01-10, UCI-ITS-AS-WP-01-5. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/15x0v29d.

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)

Trishna Chakraborty, 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.

Suggested Citation

Trishna Chakraborty and Alfred Chen (2024) How Risky Are Cyber Security Threats Against Autonomous Vehicles?. Policy Brief. UC ITS. Available at: https://doi.org/10.7922/g29p3004.

Related Publications

research report | Apr 2024

Risk Assessment for Security Threats and Vulnerabilities of Autonomous Vehicles

book/book chapter

Transit in American Cities

Publication Date

January 1, 1986

Author(s)

Gordon (Pete) Fielding

Suggested Citation

Gordon J Fielding (1986) “Transit in American Cities”, in The Geography of Urban Transportation. 2nd ed. New York: Guilford Press, pp. 229–246.

published journal article

Managing transportation

Transportation Research Part A: General

Publication Date

March 1, 1987

Author(s)

Gordon (Pete) Fielding

View published journal article

Suggested Citation

Gordon J. Fielding (1987) “Managing transportation”, Transportation Research Part A: General, 21(2), pp. 85–86. Available at: 10.1016/0191-2607(87)90001-X.

MS Thesis

A prototype real-time expert system for arterial street incident management

Publication Date

June 30, 1993

Author(s)

Dean Deeter

Areas of Expertise

Intelligent Transportation Systems, Emerging Technologies, & Big Data

View MS Thesis

Abstract

TBD

Suggested Citation

Dean Deeter (1993) A prototype real-time expert system for arterial street incident management. MS Thesis. UC Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/17uq3m8/alma991033953149704701.

published journal article

What drives variations in public health and social services expenditures? the association between political fragmentation and local expenditure patterns

The European Journal of Health Economics

Publication Date

July 1, 2022

Author(s)

Yonsu Kim, Jae Hong Kim

View published journal article

Abstract

The US spends two times more than the OECD average in health expenditure but has a much smaller portion of public health spending to total health expenditure than other OECD countries. While it has been suggested that public health and social services spending is crucial to promoting health outcomes, less is known about what drives variations in public health expenditure across regions. This study aims to examine whether political fragmentation in local governance is associated with variations in public health and social services expenditures. Using the US Census of Governments, we constructed a panel dataset of political fragmentation and local government spending patterns (1997–2012) for 792 US counties (population > 60,882, top 25%) and employed Least Squares Dummy Variable (LSDV) and Generalized Estimating Equations (GEE) models. We found that per capita public health spending tended to be smaller in areas where the degree of political fragmentation was higher (Coef: – 0.034; p < 0.01), particularly when general-purpose governments were more fragmented (Coef: – 0.087; p < 0.001). The proportion of public health spending also decreased when local governments were more fragmented (Coef: – 0.012; p < 0.001). Social services expenditures and their proportions to total government expenditure fell with an increase in the degree of political fragmentation. Our findings suggest that fragmented governance settings, in which localities are more likely to face competition with others, may lead to a reduction in public spending essential for population health and that political fragmentation can also have a deterrent effect on broader categories of health-related social services spending.

Suggested Citation

Yonsu Kim and Jae Hong Kim (2022) “What drives variations in public health and social services expenditures? the association between political fragmentation and local expenditure patterns”, The European Journal of Health Economics, 23(5), pp. 781–789. Available at: 10.1007/s10198-021-01394-x.

published journal article

Does e-shopping impact household travel? Evidence from the 2017 U.S. NHTS

Journal of Transport Geography

Publication Date

February 1, 2024

Author(s)

Lu Xu, Jean-Daniel Saphores

View published journal article

Abstract

How does e-shopping impact household travel? To answer this question, which is particularly relevant for policymakers concerned with congestion, air pollution, and greenhouse gas emissions from transportation, we analyzed data from the 2017 National Household Travel Survey using propensity score matching. This allowed us to tackle the bias from households self-selecting into various levels of e-shopping and gain causal inference. Unlike other related papers in the literature, our unit of analysis is a household because travel and shopping decisions within a household are interrelated. We classified households into three groups based on how many orders per person per month they placed online: low (up to one), medium (more than once but less than four), and high (over four). We found that more e-shopping results in more household travel (number of trips, miles, and VMT), but this effect depends on e-shopping frequency and population density, and it affects weekdays more than weekends. E-shopping impacts household travel more for medium frequency e-shoppers in low density areas: compared to similar low frequency e-shoppers, on weekdays, they take on average 8 more monthly trips and travel ∼104 extra miles (including 31 miles for shopping). At the other end of the spectrum, high frequency e-shoppers in dense areas do not travel more on weekends than similar low e-shopping frequency households. To help reduce e-shopping induced travel, policymakers could encourage the creation of neighborhood depots where households would pick-up and return unwanted orders, and foster the development of virtual reality tools for shopping from home.

Suggested Citation

Lu Xu and Jean-Daniel Saphores (2024) “Does <i>e</i>-shopping impact household travel? Evidence from the 2017 U.S. NHTS”, Journal of Transport Geography, 115, p. 103827. Available at: 10.1016/j.jtrangeo.2024.103827.

research report

A Tool for the Incorporation of Non-Recurrent Congestion Costs of Freeway Accidents in Performance Management

Publication Date

November 1, 2005

Associated Project

A Tool for the Incorporation of Non-Recurrent Congestion Costs of Freeway Accidents in Performance Management

Author(s)

Will Recker, Younshik Chung, Tom Golob

Final Report

UCB-ITS-PRR-2005-30

Areas of Expertise

Infrastructure Delivery, Operations, & Resilience Intelligent Transportation Systems, Emerging Technologies, & Big Data

View research report

Abstract

In this research, we develop and apply an analytic procedure that estimates the amount of traffic congestion (vehicle hours of delay) that is caused by different types of accidents that occur on urban freeways in California. A key feature of this research is the development of a method to separate the non-recurrent delay from any recurrent delay that is present on the road at the time and place of a reported accident, in order to estimate the contribution of non-recurrent delay caused by the specific accident. Our analysis involves a case study of accidents that occurred on freeways in Orange County in 2001. The non-recurrent delay caused by the case study accidents is estimated based on inferred link speeds derived from loop data and a binary integer programming formulation to identify the temporal and spatial region affected by the accident. Computations of non-recurrent delay were successfully performed for 870 accidents that occurred on weekdays throughout the period of March through December 2001 on the six major Orange County non-toll freeways. A statistical model was estimated that describes non-recurrent delay as a function of day of week, time of day, weather, and the observable (e.g., from emergency calls and/or aerial or on-scene observation) characteristics of the accident.

Suggested Citation

Will Recker, Younshik Chung and Tom Golob (2005) A Tool for the Incorporation of Non-Recurrent Congestion Costs of Freeway Accidents in Performance Management. Final Report UCB-ITS-PRR-2005-30. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/9sc621n5.

conference paper

The impact of a new mass rapid transit system on residential property values - the case of kaohsiung, taiwan

Transportation & logistics management

Publication Date

January 1, 2012

Author(s)

Jean-Daniel Saphores, Chung Yeh

Abstract

The construction of a public transit system in a large metropolitan area can relieve congestion, enhance mobility, and improve air quality. In a well-functioning housing market, these benefits are reflected in housing prices. In this paper, we analyze transactions for 2007 and 2009 of apartments with elevators from Kaohsiung (Taiwan’s second largest city) using a geographically weighted regression hedonic model to capture the impact of the opening in 2008 of a new mass rapid transit (MRT) system. We find that the opening of the MRT had a statistically significant and positive impact on the value of apartments with elevators that was not yet fully capitalized in 2007 prices.

Suggested Citation

Jean-Daniel Saphores and Chung-Cheng Yeh (2012) “The impact of a new mass rapid transit system on residential property values - the case of kaohsiung, taiwan”, in . Mak, HY and Lo, HK (ed.) Transportation & logistics management. HONG KONG SOC TRANSPORTATION STUDIES LTD, pp. 89–96.

published journal article

A new approach to estimate vehicle emissions using inductive loop detector data

Journal of Intelligent Transportation Systems

Publication Date

July 1, 2012

Author(s)

Shin-Ting (Cindy) Jeng, Nesamani Kalandiyur, Stephen Ritchie

View published journal article

Suggested Citation

Shin-Ting (Cindy) Jeng, K.S. Nesamani and Stephen G. Ritchie (2012) “A new approach to estimate vehicle emissions using inductive loop detector data”, Journal of Intelligent Transportation Systems, 17(3), pp. 179–190. Available at: 10.1080/15472450.2012.712495.