published journal article

Travel Time Reliability with Risk-Sensitive Travelers

Transportation Research Record: Journal of the Transportation Research Board

Publication Date

January 1, 2002

Author(s)

Anthony Chen, Zhaowang Ji, Will Recker

Abstract

In recent empirical studies on values of time and reliability, many have suggested that travelers are interested not only in travel time saving but also in reduction in travel time variability. Variability introduces uncertainty for travelers such that they do not know exactly when they will arrive at their destination. Thus, it is considered as a risk (or an added cost) to a traveler making a trip. Continuing research is reported on route choice models and the effect on travel time reliability in an uncertain environment caused by demand and supply variations. The goal is to examine what the aggregate impact of changes in variability might be on network assignment and how travelers with different risk-taking behaviors respond to these changes.

Suggested Citation
Anthony Chen, Zhaowang Ji and Will Recker (2002) “Travel Time Reliability with Risk-Sensitive Travelers”, Transportation Research Record: Journal of the Transportation Research Board, 1783(1), pp. 27–33. Available at: 10.3141/1783-04.

Phd Dissertation

Investigation of LiDAR sensor for Traffic Monitoring with Emphasis on Heavy Duty Trucks

Abstract

Traffic Monitoring is at the center of any Intelligent Transport System. Current traffic monitoring sensors are challenged to deliver in the evolving landscape of connected, autonomous and alternative fuel transportation systems. This dissertation explores the feasibility of emerging LiDAR technology for traffic monitoring, in an infrastructure-based, side-fire LiDAR configuration. LiDAR technology was investigated in terms of providing both the core data elements of existing traffic monitoring systems such as vehicle counts and speeds, as well as more high-resolution data elements required for future connected and autonomous vehicles such as relative positions of vehicles on a roadway, vehicle lateral and longitudinal positions within a lane, physical attributes of individual vehicles, and vehicle microscopic trajectories. LiDAR sensors were deployed at both dense urban corridors and rural highway locations. At the urban location, the LiDAR estimate of vehicle counts across lanes was between 87% to 110% of a baseline calibrated sensor’s vehicle counts. At the rural highway location, microscopic trajectories for vehicles were derived at 0.1 second resolution, enabling detection of anomalies in vehicle behavior. In addition, the precise lateral positions of heavy-duty vehicles were derived at the urban corridor location, with a particular interest being future safety assessment for loss of control of autonomous heavy-duty trucks. The high-resolution traffic data elements derived from this research can assist in detecting anomalous behavior of vehicles, whether from impaired driving or loss of effective autonomous control, with road safety assessments, and in providing inputs for microscopic road emission modeling.

Suggested Citation
Koti Reddy Allu (2024) Investigation of LiDAR sensor for Traffic Monitoring with Emphasis on Heavy Duty Trucks. Ph.D.. UC Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/17uq3m8/alma991035600657004701 (Accessed: October 23, 2024).

conference paper

A Non-intrusive and Influences-agnostic Impaired Driving Detection and Control Framework using LIDAR

102nd Annual Meeting of the Transportation Research Board

Publication Date

January 1, 2023
Suggested Citation
Montana Reinoehl, Siwei Hu and Koti Reddy Allu (2023) “A Non-intrusive and Influences-agnostic Impaired Driving Detection and Control Framework using LIDAR”. 102nd Annual Meeting of the Transportation Research Board.

published journal article

Urban extremism

Journal of Law, Economics, and Organization

Publication Date

November 1, 2007

Abstract

A current majority in some city, seeking to increase the probability that it will set policy in the following period, may initially adopt extremist policies that are particularly unattractive to the minority, leading some members of the minority to emigrate. This article develops a model to illustrate this idea, while providing examples that illustrate its relevance. (JEL H70, H41, D72)

Suggested Citation
J.K. Brueckner and A. Glazer (2007) “Urban extremism”, Journal of Law, Economics, and Organization, 24(2), pp. 307–318. Available at: 10.1093/jleo/ewm058.

conference paper

Real-time mass transport vehicle routing problem: Local routing with global optimization

Proceedings of the 86th annual meeting of the transportation research board

Publication Date

January 1, 2007

Abstract

This paper categorizes and solves a new class of problems called Real-Time Mass Transport Vehicle Routing Problems (MTVRP). The aim of these problems is to find a solution to optimally route vehicles in real time to pick up and deliver more passengers. This problem is described in the context of flexible large-scale mass transport options that use new technologies for communication among passengers and vehicles. The problem is very relevant to future transportation options involving large scale real-time routing of shared-ride fleet transit vehicles. However the global optimization of such a problem has not been studied in the past. Previous research by the authors (1) described MTVRP and proposed a three level hierarchical optimization process. The earlier work had shown the theoretical solutions for the first two levels giving globally optimal parameters. This paper implements the third step of the process, namely the Local Mass Transport Vehicle Routing Problem (LMTVRP) and demonstrates the efficacy of the scheme with simulation of LMTVRP scheme that uses globally optimal parameters. The paper also presents a classification of MTVRP among other Vehicle Routing Problems (VRPâ??s), and provides the simulation results from the application of MTVRP in a real urban network, namely, Barcelona, Spain.

Suggested Citation
Laia Pages and R. Jayakrishnan (2007) “Real-time mass transport vehicle routing problem: Local routing with global optimization”, in Proceedings of the 86th annual meeting of the transportation research board, p. 22p.

published journal article

Intelligent Transportation Systems: Research Products for Public Works Professionals

Public Works Management & Policy

Publication Date

July 1, 2000

Author(s)

Patrick Conroy, Steven Shladover, Joy Dahlgren, Pravin Varaiya, Will Recker, Stephen Ritchie

Abstract

Intelligent transportation systems (ITS) hold great promise for public works professionals seeking to optimize those public investment strategies that deal with traffic congestion and other growth pressures. Advanced traffic and fleet management systems as well as traveler information and vehicle-based systems can take advantage of information technology advances and private market products to substantially improve the productivity, connectivity, and safety of transportation. And as the new federal transportation act further spurs deployment of these systems, ITS research programs will continue to play a vital role in supporting such deployment and the overall evolution of ITS. Such research includes developing technology tools, providing testing and evaluation environments, and helping advance the state of the practice.

Suggested Citation
Patrick Conroy, Steven Shladover, Joy Dahlgren, Pravin Varaiya, Will Recker and Stephen Ritchie (2000) “Intelligent Transportation Systems: Research Products for Public Works Professionals”, Public Works Management & Policy, 5(1), pp. 3–12. Available at: 10.1177/1087724X0051001.

published journal article

Relationships among urban freeway accidents, traffic flow, weather, and lighting conditions

Journal of Transportation Engineering

Abstract

Linear and nonlinear multivariate statistical analyses are applied to determine how the types of accidents that occur on heavily used freeways in Southern California are related both to the flow of traffic and to weather and ambient lighting conditions. Traffic flow is measured in terms of time series of 30-s observations from inductive loop detectors in the vicinity of the accident prior to the time of its occurrence. Results indicate that the type of collision is strongly related to median traffic speed and to temporal variations in speed in the left and interior lanes. Hit-object collisions and collisions involving multiple vehicles that are associated with lane-change maneuvers are more likely to occur on wet roads, while rear-end collisions are more likely to occur on dry roads during daylight. Controlling for weather and lighting conditions, there is evidence that accident severity is influenced more by volume than by speed.

Suggested Citation
Thomas F. Golob and Wilfred W. Recker (2003) “Relationships among urban freeway accidents, traffic flow, weather, and lighting conditions”, Journal of Transportation Engineering, 129(4), pp. 342–353. Available at: 10.1061/(asce)0733-947x(2003)129:4(342).

journal article preprint

A Simultaneous Model of Household Activity Participation and Trip Chain Generation

Publication Date

March 22, 1999

Associated Project

Author(s)

Abstract

A trip generation model has been developed using a time-use perspective, in which trips are generated in conjunction with out-of-home activities, and time spent traveling is another component of overall time use. The model jointly forecasts three sets of endogenous variables- (1) activity participation and (2) travel time (together making up total out-of-home time use) and (3) trip generation – as a function of household characteristics and accessibility indices. It is estimated with data from the Portland, Oregon  1994 Activity and Travel Survey. Results show that the basic model, which has ten endogenous time use and trip generation variables and thirteen exogenous variables, fits well, and all postulated relationships are upheld. Test show that the basic model, which divides activities into work and nonwork, can be extended to a three-way breakdown of subsistence, discretionary and obligatory activities. The model can also capture the effects of in-home work on trip chaining and activity participation. We use the model to explore the effects on time use and trip chaining of GIS-based and zone-based accessibility indices.  

working paper

Real-World CO2 Impacts of Traffic Congestion

Abstract

Transportation plays a significant role in carbon dioxide (CO2) emissions, accounting for approximately a third of the United States’ inventory. In order to reduce CO2 emissions in the future, transportation policy makers are looking to make vehicles more efficient and increasing the use of carbon-neutral alternative fuels. In addition, CO2 emissions can be lowered by improving traffic operations, specifically through the reduction of traffic congestion. This paper examines traffic congestion and its impact on CO2 emissions using detailed energy and emission models and linking them to real-world driving patterns and traffic conditions. Using a typical traffic condition in Southern California as example, it has been found that CO2 emissions can be reduced by up to almost 20% through three different strategies: 1) congestion mitigation strategies that reduce severe congestion, allowing traffic to flow at better speeds; 2) speed management techniques that reduce excessively high free-flow speeds to more moderate conditions; and 3) shock wave suppression techniques that eliminate the acceleration/deceleration events associated with stop-and-go traffic that exists during congested conditions.

working paper

Measuring Traffic Congestion

Publication Date

September 5, 1998

Working Paper

UCI-ITS-WP-98-3

Areas of Expertise

Abstract

We develop a traffic congestion index using data for California highways from 1976 through 1994. The technique yields a congestion measure which has several advantages. The index developed here can be applied to counties, urbanized areas, highway segments, or other portions of geographic areas or highway networks. The index allows cross-sectional and time series comparisons which have only rarely been possible. Most importantly, the congestion index developed here is based on data which are readily available. We compare our index to others based on Highway Performance Monitoring System (HPMS) data, and illustrate similarities and differences. We also discuss important issues for future research and data collection efforts which can contribute to more refined congestion measurement.

Suggested Citation
Marlon G. Boarnet, Eugene Jae Kim and Emily Parkany (1998) Measuring Traffic Congestion. Working Paper UCI-ITS-WP-98-3. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/2hr1k5s0.