working paper

Impacts of Highway Congestion on Freight Operations: Perceptions of Trucking Industry Managers

Abstract

To better understand how road congestion adversely affects trucking operations, we surveyed approximately 1200 managers of all types of trucking companies operating in California. More than 80% of these managers consider traffic congestion on freeways and surface streets to be either a “somewhat serious” or “critically serious” problem for their business. A structural equations model (SEM) is estimated on these data to determine how five aspects of the congestion problem differ across sectors of the trucking industry. The five aspects were slow average speeds, unreliable travel times, increased driver frustration and morale, higher fuel and maintenance costs, and higher costs of accidents and insurance. The model also simultaneously estimates how these five aspects combine to predict the perceived overall magnitude of the problem. Overall, congestion is perceived to be a more serious problem by managers of trucking companies engaged in intermodal operations, particularly private and for-hire trucking companies serving airports and private companies serving rail terminals. Companies specializing in refrigerated transport also perceive congestion to be a more serious overall problem, as do private companies engaged in LTL operations. The most problematic aspect of congestion is unreliable travel times, followed by driver frustration and morale, then by slow average speeds. Unreliable travel times are a significantly more serious problem for intermodal air operations. Driver frustration and morale attributable to congestion is perceived to be more of a problem by managers of long-haul carriers and tanker operations. Slow average speeds are also more of a concern for airport and refrigerated operations.

published journal article

Analysis and visualization method for understanding the voltage effect of distributed energy resources on the electric power system

Electric Power Systems Reserch

Publication Date

January 1, 2012

Author(s)

Allie E. Auld, Jack Brouwer, Scott Samuelsen
Suggested Citation
Allie E. Auld, Jack Brouwer and G. Scott Samuelsen (2012) “Analysis and visualization method for understanding the voltage effect of distributed energy resources on the electric power system”, Electric Power Systems Reserch, 82(1), pp. 44–53. Available at: 10.1016/j.epsr.2011.08.012.

published journal article

Selective vehicle routing problems under uncertainty without recourse

Transportation Research Part E: Logistics and Transportation Review

Publication Date

February 1, 2014
Suggested Citation
Mahdieh Allahviranloo, Joseph Y.J. Chow and Will W. Recker (2014) “Selective vehicle routing problems under uncertainty without recourse”, Transportation Research Part E: Logistics and Transportation Review, 62, pp. 68–88. Available at: 10.1016/j.tre.2013.12.004.

published journal article

Security analysis for fixed-time traffic control systems

Transportation Research Part B: Methodological

Publication Date

September 1, 2020

Abstract

Wireless communication is being used as an enabling technology with traditional fixed traffic control systems in this transitional era toward Intelligent Transportation Systems (ITS). Unfortunately, major security concerns have arisen with respect to ever-increasing complexity and interconnectivity, and a noticeable lack of attention for security in these systems. Addressing concerns is a colossal challenge as it requires thorough development and formal analysis of a system model with respect to security. To tackle this challenge, we present a novel formal attack modeling and impact analysis methodology based on the Link Queue Model (LQM) of traffic flow inside a double ring road network, which is equivalent to a grid network with homogeneous links. We develop attack models as functions of tampered traffic control settings (e.g., green time ratios, cycle length, retaining ratios) with outputs equivalent to mobility impacts on the traffic network (e.g., time until system reaches state convergence, asymptotic average network flow). Further, for a given attack model, we define and identify vulnerable states: states that are critical to protect because they lead to negative impacts under the given attack model. Using our methodology we found that for certain vulnerable states, after only a few cycles of tampered control settings an attacker could cause a real impact of 1.5x speed-up in gridlock state convergence or 37%-99% drop in the asymptotic average flow rate. These results imply potentially drastic financial costs for cities and all involved drivers if similar attacks were performed on a real traffic control system. (C) 2020 Elsevier Ltd. All rights reserved.

Suggested Citation
Anthony Lopez, Wenlong Jin and Mohammad Abdullah Al Faruque (2020) “Security analysis for fixed-time traffic control systems”, Transportation Research Part B: Methodological, 139, pp. 473–495. Available at: 10.1016/j.trb.2020.07.002.

published journal article

Public Transit Performance Evaluation: Application to Section 15 Data

Transportation Research Record

Publication Date

January 1, 1983

Author(s)

Shirley C Anderson, Gordon (Pete) Fielding

Abstract

Performance indcators are quantitative measures that enable managers and policymakers to monitor the current position of an agency and outline strategies to improve performance. Because public services have many different dimensions of performance, a large number of performance indicators are normally used. In this paper a conceptual model is used to help select a few performance indicators that represent all the important performance concepts. Data were obtained from a national sample of 311 urban bus transit systems in the first year that data were reported under Section 15 of the Urban Mass Transportation Act of 1965, as amended. The steps in the performarice-evaluatlon procedure Involve defining a conceptual model of performance and designing a balancod set of performance indicators that represent all performance concepts. Factor analysis is then used to select the indicators that best represent all dimensions of performance. This smell, representative set of performance Indicators is used to analyze performance and to establish peer-group rankings.

Suggested Citation
Shirley C Anderson and Gordon J. Fielding (1983) “Public Transit Performance Evaluation: Application to Section 15 Data”, Transportation Research Record, (947), pp. 1--6. Available at: https://onlinepubs.trb.org/Onlinepubs/trr/1983/947/947-001.pdf.

published journal article

Marketing implications of perceptions of transit

TRANSPORTATION ENGINEERING JOURNAL OF ASCE

Publication Date

January 1, 1982

Author(s)

Ww Recker, Hj Schuler
Suggested Citation
Ww Recker and Hj Schuler (1982) “Marketing implications of perceptions of transit”, TRANSPORTATION ENGINEERING JOURNAL OF ASCE, 108(6), pp. 650–661.

research report

Spatial analysis of bicycling ridership patterns from bias-corrected crowdsourced data

Abstract

This study leverages big data from the Strava Metro app, integrated with official count data from the Orange County Transportation Authority, to analyze spatial patterns of bicycling ridership in Orange County, California. By applying bias correction techniques to crowdsourced data and incorporating land use and socioeconomic covariates, the study generate a comprehensive map of ridership volumes across the region. The study’s analysis reveals significant spatial autocorrelation in cycling activity, with distinct patterns between coastal and inland areas. Coastal regions exhibit strong High-High clusters, indicating concentrated cycling activity, while inland areas show a more varied pattern with Low-High clusters and isolated High-High pockets. These findings demonstrate the potential of bias-corrected crowdsourced data to inform targeted infrastructure planning in both urban and suburban contexts. By identifying areas of high cycling demand and potential growth, this methodology provides valuable insights for policymakers and urban planners to enhance cycling infrastructure and promote sustainable transportation in diverse geographic settings, from coastal cities to inland communities.

Suggested Citation
Avipsa Roy and Ghangshin Lee (2025) Spatial analysis of bicycling ridership patterns from bias-corrected crowdsourced data. Final Report PSR-22-24-TO 069. PSR / ITS-Irvine. Available at: https://www.metrans.org/assets/research/psr-22-24%20to-069%20avipsa%20roy.pdf.

published journal article

Spatiotemporal analysis of traffic congestion caused by rubbernecking at freeway accidents

IEEE Trans. Intell. Transport. Syst.

Publication Date

September 1, 2013
Suggested Citation
Younshik Chung and Wilfred W. Recker (2013) “Spatiotemporal analysis of traffic congestion caused by rubbernecking at freeway accidents”, IEEE Trans. Intell. Transport. Syst., 14(3), pp. 1416–1422. Available at: 10.1109/tits.2013.2261987.

policy brief

COVID-19 Vaccination Rates Influenced Bus Ridership Recovery

Abstract

COVID-19 has had lasting effects on transit ridership, with the worst declines seen in high-income, better educated, urban neighborhoods. However, declines among immigrant and/or low-income households was well documented prior to the pandemic, as more gained access to private vehicles. This has created a unique challenge for transit agencies to bring riders back to transit in cases where they may have already switched to traveling by car or consciously chose to make fewer trips. To better understand ridership during the pandemic, we documented the recovery of bus ridership in Los Angeles County and its relationship with COVID-19 vaccinations between April and December 2021, before the Omicron COVID-19 wave. We then developed a statistical model that relates LA Metro bus ridership as a percentage of October 2019 levels with the percent of adults fully vaccinated by ZIP code. We tested whether the relationship between vaccinations and bus ridership varied by two events: first, the full reopening of businesses in California and second, the wave of COVID transmission caused by the subsequentDelta variant.

Suggested Citation
David Brownstone and Henry Bernal (2024) COVID-19 Vaccination Rates Influenced Bus Ridership Recovery. Policy Brief. UC ITS. Available at: https://doi.org/10.7922/g2k935wj.

conference paper

The California ATMS Testbed Research Program: An Overview

Proceedings, IVHS America Annual Conference

Publication Date

January 1, 1995

Author(s)

Suggested Citation
Wilfred W. Recker (1995) “The California ATMS Testbed Research Program: An Overview”, in Proceedings, IVHS America Annual Conference. Washington, D. C..