Area of Expertise: Unspecified

published journal article

A method for relating type of crash to traffic flow characteristics on urban freeways

Transportation Research Part A: Policy and Practice

Publication Date

January 1, 2004

Author(s)

Thomas Golob, Will Recker
View published journal article

Abstract

(A) method is developed to determine how crash characteristics are related to, traffic flow conditions at the time of occurrence. Crashes are described in terms of the type and location of the collision, the number of vehicles involved, movements of these vehicles prior to collision, and severity. Traffic flow is characterized by central tendencies and variations of traffic flow and flow/occupancy for three different lanes at the time and place of the crash. The method involves nonlinear canonical correlation applied together with cluster analyses to identify traffic flow regimes with distinctly different crash taxonomies. A case study using data for more than 1000 crashes in Southern California identified twenty-one traffic flow regimes for three different ambient conditions: dry roads during daylight (eight regimes), dry roads at night (six regimes), and wet conditions (seven regimes). Each of these regimes has a unique profile in terms of the type of crashes that are most likely to occur, and a matching of traffic flow parameters and crash characteristics reveals ways in which congestion affects highway safety. (C) 2003 Elsevier Ltd. All rights reserved.

Suggested Citation
Thomas F Golob and Wilfred W Recker (2004) “A method for relating type of crash to traffic flow characteristics on urban freeways”, Transportation Research Part A: Policy and Practice, 38(1), pp. 53–80. Available at: 10.1016/j.tra.2003.08.002.

MS Thesis

Data Analysis of the 2000 SCAG Post-Census Regional Travel Survey and the 2010-2012 California Household Travel Survey

Publication Date

January 1, 2015

Author(s)

Andrew Timothy, Andrew Timothy
View MS Thesis

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 Kimble Timothy (2015) Data Analysis of the 2000 SCAG Post-Census Regional Travel Survey and the 2010-2012 California Household Travel Survey. MS Thesis. University of California, Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/17uq3m8/alma991023228619704701.

working paper

Towards Distributed Data Collection and Peer-to-Peer Data Sharing

Publication Date

August 1, 2002

Author(s)

James Marca, Craig Rindt, Michael McNally

Working Paper

UCI-ITS-WP-02-15, UCI-ITS-AS-WP-02-15
View working paper

Abstract

Two recent technological events should be examined more closely for their applicability to ATMIS and other ITS systems. First, the recent rise of wireless LAN protocols such as 802.11b should be studied for use in a vehicle context. Second, the rise and fall of Napster, followed by increased development on more decentralized protocols such as Gnutella and Freenet are leading to an increasingly robust peer-to-peer platforms. This paper argues that peer-to-peer communication and local area wireless networks should play a central role in any system to distribute traveler information services. Instead, the National ITS Architecture makes no mention of peer-to-peer information exchange, relegating local area wireless connections to vehicle control.

Suggested Citation
James E. Marca, Craig R. Rindt and Michael G. McNally (2002) Towards Distributed Data Collection and Peer-to-Peer Data Sharing. Working Paper UCI-ITS-WP-02-15, UCI-ITS-AS-WP-02-15. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/6kt6q702.

working paper

Structural Equation Modeling of Travel Choice Dynamics

Publication Date

June 1, 1988

Author(s)

Thomas Golob

Working Paper

UCI-ITS-WP-88-13, UCI-ITS-AS-WP-88-1
View working paper

Abstract

This research has two objectives. The first objective is to explore the use of the modeling tool called “latent structural equations” (structural equations with latent variables) in the general field of travel behavior analysis and the more specific field of dynamic analysis of travel behavior. The second objective is to apply a latent structural equation model in order to determine the causal relationships between income, car ownership, and mobility. Many transportation researchers might be unfamiliar with latent structural equation modeling, which is also known as “latent structural analysis,” “causal analysis,” and “soft modeling.” However, most researchers will be quite familiar with techniques that are special cases of latent structural equations: e.g., conventional multiple regression and simultaneous equations, path analysis, and (confirmatory) factor analysis. Furthermore, recent advances in estimation techniques have made it possible to incorporate discrete choice variables and other non-normal variables in structural equations models. Thus, probit choice models (binomial, ordered, and multinomial) can be incorporated within the general model framework. The empirical analysis reported here involves dynamic travel demand data from the Dutch National Mobility Panel for the three years 1984 through 1986. All variables in the model, with the exception of income level in the first year, are endogenous: income is treated as an ordinal (four category) variable; car ownership is treated as either an ordinal (ordered probit) or a categorical (multinomial probit) choice variable; and mobility, in terms of car trips and public transport trips, is treated as two censored (tobit) continuous variables. The model fits the data well, but only scratches the surface of the potential of latent structural equation modeling with panel data. Some possible extensions are outlined.

Suggested Citation
Thomas F. Golob (1988) Structural Equation Modeling of Travel Choice Dynamics. Working Paper UCI-ITS-WP-88-13, UCI-ITS-AS-WP-88-1. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/8kg9s6zb.

conference paper

Incorporating time-of-day utility in the household activity pattern problem

Proceedings of the 94th annual meeting of the transportation research board

Publication Date

January 1, 2015

Author(s)

Daji Yuan, Will Recker

Abstract

This paper provides extensions to the Household Activity Pattern Problem (HAPP) to help move existing formulations from a laboratory prototype toward a more usable activity-based demand modeling product. Previous research on HAPP has been based on a pickup and delivery problem with time window constraints (PDPTW), which does not lend itself easily to application compatible with an activity-based forecasting model. Meanwhile, other research on activity based modeling lacks of the integration of household decisions on time of day arrival, activity duration and traffic congestion effect on travel. For the demand side, the authors propose to incorporate time-of-day factors influencing both activity arrival and activity duration utility into HAPP as decision variables. Alternatively, for the supply side, the authors extend HAPP to capture the time-of-day (TOD) differences in travel times and costs to form the travel time-dependent utility household activity pattern problem model (TUHAPP). In their synthetic examples, the authors demonstrate how TUHAPP handles impacts of policy changes on peopleâ??s departure and activity duration decisions and how traffic congestion can change peopleâ??s travel agendas.

Suggested Citation
Daji Yuan and Will Recker (2015) “Incorporating time-of-day utility in the household activity pattern problem”, in Proceedings of the 94th annual meeting of the transportation research board, p. 23p.

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