working paper

Airport choice and airline choice in the market for air travel between the San Francisco Bay area and greater Los Angeles in 1995

Publication Date

August 31, 2005

Author(s)

Kurt van-Dender

Areas of Expertise

Travel Behavior, Land Use, & the Built Environment

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Abstract

This paper empirically investigates the impact of airport and airline supply characteristics on the air travel choices of passengers departing from one of three San Francisco Bay area airports and arriving at one of four airports in greater Los Angeles. It does so by estimating a conditional logit model for the market of air travel between both metropolitan areas in 1995, and using the estimated model to simulate three counterfactual scenarios. First, reducing access times to San Francisco International airport by 10% for all travelers increases the market share of that airport by 4.5%-point. United Airlines benefits from the reduced access times, as its market share increases by 2.9%-point. Second, reducing average delays at San Francisco International airport by 10% has similar aggregate effects to the first scenario, but indicates that leisure travelers value access time reductions more than reduced delays. Third, entry of Southwest airlines in San Francisco International airport increases the market share of Southwest airlines by 5%-point to 15-%point, depending on assumptions concerning its continuation of services at Oakland International Airport, and assuming that rival carriers do not respond in terms of prices or service levels.

working paper

Real-Time Mass Passenger Transport Network Optimization Problems

Publication Date

May 31, 2005

Author(s)

Laia Pages, R. (Jay) Jayakrishnan, Cristian Cortes

Areas of Expertise

Public Transit, Shared Mobility, & Active Transportation

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Abstract

The aim of Real-Time Mass Transport Vehicle Routing Problem (MTVRP) is to find a solution to route n vehicles in real time to pick up and deliver m passengers. This problem is described in the context of flexible large-scale mass transportation options that use new technologies for communication among passengers and vehicles. The solution of such a problem is relevant to future transportation options involving large scale real-time routing of shared-ride fleet transit vehicles. However, the global optimization of a complex system involving routing and scheduling multiple vehicles and passengers as well as design issues has not been strictly studied in the past. This research proposes a methodology to solve it by using a three level hierarchical optimization approach. Within the optimization process, a Mass Transport Network Design Problem (MTNDP) is solved. This paper introduces MTVRP and presents a scheme to solve it. Then, the associated algorithm to perform the MTNDP optimization is described in detail. An instance for the city of Barcelona, Spain is solved, showing promising results with regard to the applicability of the methodology for large scale transit problems.

working paper

Mass Transport Vehicle Routing Problem (MTVRP) and the Associated Network Design Problem (MTNDP)

Publication Date

May 31, 2005

Author(s)

R. (Jay) Jayakrishnan, Laia Pages

Areas of Expertise

Public Transit, Shared Mobility, & Active Transportation

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Abstract

This research studies a new class of dynamic problem MTVRP where n vehicles are routed in real time in a fast varying environment to pickup and deliver m passengers when both n and m are big. The problem is very relevant to future transportation options involving large scale real-time routing of shared-ride fleet transit vehicles. Traditionally, dynamic routing solutions were found as static approximations for smaller-scale problems or using local heuristics for the larger-scale ones. Generally heuristics used for these types of problems do not consider global optimality. A hierarchical method to solve the MTVRP in three different stages has been developed. Within the optimization process, a particular case of Network Design Problem (NDP) is solved. This paper introduces MTVRP and presents a scheme to solve it. Then, it describes the associated Mass Transport Network Design Problem (MTNDP) and solves the problem. The computational complexities as well as the results are compared.

working paper

Death on the Crosswalk: A Study of Pedestrian-Automobile Collisions in Los Angeles

Publication Date

March 31, 2005

Author(s)

Anastasia Loukaitou-Sideris

Areas of Expertise

Infrastructure Delivery, Operations, & Resilience Safety, Public Health, & Mobility Justice

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Abstract

This research explores the spatial distribution of pedestrian-automobile collisions in Los Angeles and analyzes the social and physical factors that affect the risk of getting involved in such accidents. More specifically, this study investigates the influence of socio-demographic, land use, density, and traffic characteristics on pedestrian accident rates.

We first provide an exploratory spatial and statistical analysis of pedestrian collision data in the city of Los Angeles to identify preliminary relationships between accident frequency and socio-demographic and land use characteristics at the census tract and block group levels. This aggregate level analysis also helps us identify major concentrations of pedestrian collision data which are used at a second stage of the research for more qualitative and detailed analysis of specific case studies of intersections with high frequency of pedestrian-automobile accidents. The study uses pedestrian accident data provided by the Los Angeles Department of Transportation, traffic volume data provided by Caltrans, socio-demographic data from the U.S. Census 2000, land use data from the Southern California Association of Governments (SCAG), and pedestrian volume and built environment data from fieldwork research.

working paper

Dynamic Path-Based Equilibrium Assignment With Microscopic Traffic Simulation

Publication Date

March 31, 2005

Author(s)

Henry Liu, Will Recker

Areas of Expertise

Infrastructure Delivery, Operations, & Resilience

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Abstract

This report summarizes research work conducted under TO4158 at the California ATMS Testbed of the Institute of Transportation Studies at the University of California, Irvine. Under this task order, the California ATMS testbed hosted two full-time PATH research postdocs (Henry Liu and Lianyu Chu) whose general responsibilities are focused on applications of ATMS in the Testbed environment. They are generally responsible for ensuring that the functional capabilities of the Testbed are designed, developed and maintained in a manner that complements and enhances the ATMS research objectives of the PATH program. Under the direction of PATH faculty researchers at UCI and the Testbed management team, they are generally responsible for software enhancements to the Laboratory “bench-top” system for modeling and evaluating ATMS, particularly with the microscopic simulation model Paramics. They also provided Caltrans the on-call support and technical guidance on various Caltrans micro-simulation projects related to the Paramics plugin modules developed at UCI. In addition to the general responsibilities outlined above, the PATH Researchers have specific research projects. The specific research project conducted under this task order is to develop a path-based equilibrium assignment model with micro-simulator Paramics. Since off-the-shlef Paramics can only do the link-based assignment, no path information during the traffic assignment process is stored nor provided. This will bring difficulties in the ATMS evaluation particularly related to the route diversion because partial or full path information is needed to conduct this type of evaluation with Paramics. To overcome this difficulty, a path-based assignment model is developed using Paramics Application Programming Interfaces (API) functions. The model comprises the advantages of the analytical traffic assignment model and the good properties of the simulation tools, which can represented the real world more properly. Some key techniques, route choice plug-in, turn penalty consideration and methods of successive average, and etc., were applied in the model. The Paramics V4 was selected as the demonstration simulation tool. A real grid network in Tucson, Arizona, was designed to test the performance of the model, and the results showed that the model converged to the user equilibrium as expected.

working paper

Development of the Capability-Enhanced PARAMICS Simulation Environment

Publication Date

March 31, 2005

Author(s)

Lianyu Chu, Henry Liu, Michael McNally, Will Recker

Areas of Expertise

Infrastructure Delivery, Operations, & Resilience

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Abstract

This report summarizes research work conducted under TO4304 at the University of California, Irvine. Under this task order, the research team provided Caltrans with on-call direct support, technical guidance, and research related support. A series of Paramics plug-ins were developed and have been released to Caltrans. These plug-ins include actuated signal, multiple actuated signal timing plan, actuated signal coordination, detector data aggregator, ramp metering control, on-ramp queue override control, ALINEA ramp metering control, BOTTLENECK ramp metering control, SWARM Ramp metering control, and Freeway MOE. They complement the current Paramics simulation model and enhance its functionalities. This report describes how we developed these plug-ins and the step-by-step procedure to use them. It can be used as user manuals.

working paper

Anonymous Vehicle Tracking for Real-Time Freeway and Arterial Street Performance Measurement

Publication Date

February 28, 2005

Author(s)

Stephen Ritchie, Seri Park, Cheol Oh, Shin-Ting (Cindy) Jeng, Andre (Yeow Chern) Tok

Areas of Expertise

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

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Abstract

This research involved an important extension of existing field-implemented and tested PATH research by the authors on individual vehicle reidentification, to develop methods for assessing freeway and arterial (and transit) system performance for the Caltrans PeMS (Performance Measurement System). PeMS has been adopted by Caltrans as the standard tool for assessing freeway system performance, but lacks capabilities for assessing arterial and transit system performance, and strategies that combine freeways, arterials and/or transit and commercial vehicle fleets. It was shown that the research methodology of this project could directly address these limitations in PeMS. A systematic investigation was conducted of anonymous vehicle tracking using existing inductive loop detectors on both freeway and arterial street facilities combined with new, low-cost high-speed scanning detector cards (that were utilized by the authors in PATH TO 4122) to meet the needs of PeMS. Both field data and microscopic simulation were utilized in a major travel corridor setting, using the Paramics simulation model and field sites that were part of the California ATMS (Advanced Transportation Management Systems) testbed network in Irvine, California. The experience and insights of the research team obtained from extensive previous and current PATH research on vehicle reidentification techniques for single roadway segments and signalized intersections was used to investigate and develop methods for tracking individual vehicles (including specified classes of vehicle such as buses and trucks) across multiple detector stations on a freeway and an arterial street network to obtain real-time performance measurements (including dynamic or time-varying origin-destination (OD) path flow information such as path travel time and volume). This study presented a framework for studying the feasibility of an anonymous vehicle tracking system for real-time freeway and arterial traffic surveillance and performance measurement. The potential feasibility of such an approach was demonstrated by simulation experiments for both a freeway and a signalized arterial operated by actuated traffic signal controls. Synthetic vehicle signatures were generated to evaluate the proposed tracking algorithm under the simulation environment. The PARAMICS microscopic simulation model was used to investigate the proposed vehicle tracking algorithm. The findings of this study can serve as a logical and necessary precursor to possible field implementation of the proposed system in freeway and arterial network. It is also believed that the proposed method for evaluating a traffic surveillance system using microscopic simulation in this study can offer a valuable tool to operating agencies interested in realtime congestion monitoring, traveler information, control, and system evaluation. Furthermore, the automatic vehicle classification system developed in this study showed very encouraging results.

research report

Field Investigation of Advanced Vehicle Reidentification Techniques and Detector Technologies - Phase 2

Publication Date

February 28, 2005

Associated Project

Field Investigation of Advanced Vehicle Reidentification Techniques and Detector Technologies-Phase 2

Author(s)

Stephen Ritchie, Seri Park, Cheol Oh, Shin-Ting (Cindy) Jeng, Andre (Yeow Chern) Tok

Areas of Expertise

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

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Abstract

This report presents the results of Phase 2 of a multi-year research effort on “Field Investigation of Advanced Vehicle Reidentification Techniques and Detector Technologies.” Phase I of this research was conducted under PATH MOU 3008. Phases I and II of this research extended previous PATH research by the authors on MOU 336 “Section-Related Measures of Traffic System Performance: Prototype Field Implementation.” Phase II of this research continued development, field investigation and assessment of the latest technologies available for traffic detection and surveillance, for collecting more accurate traffic characteristics and traffic data necessary for Intelligent Transportation Systems (ITS) applications. The focus of Phase II of this research was to utilize fully instrumented freeway and signalized intersection sites in the California Advanced Transportation Management Systems Testbed in Southern California for field investigation of several emerging traffic sensor and detector technologies for vehicle reidentification (REID) purposes and real-time traffic performance measurement. As part of this project, a traffic detector and surveillance sub-testbed (TDS 2) on North I-405 in Irvine became operational in August 2002, and the ability to perform REID-based real-time traffic performance measurement in TDS 2, developed as part of this research, and including section travel times, traffic origins and destinations, and vehicle classification, was demonstrated on-line at the PATH Annual Meeting in October 2002. The very encouraging results obtained to date by developing and applying a vehicle reidentification approach for real-time traffic performance measurement suggest that further development, implementation and testing of this approach would clearly be of value.

working paper

The Impact of Residential Density on Vehicle Usage and Energy Consumption

Publication Date

February 17, 2005

Author(s)

Thomas Golob, David Brownstone

Areas of Expertise

Travel Behavior, Land Use, & the Built Environment Zero-Emission Vehicles & Low-Carbon Fuels

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Abstract

The debate concerning the impacts of urban land use density on travel in general, and on residential vehicle use and fuel consumption in particular, lacks reliable quantitative evidence. The 2001 U.S. National Household Transportation Survey (NHTS) provides information on vehicle miles of travel (VMT) based on odometer data, as well as annual fuel usage computations based on information about the make, model and vintage of all household vehicles. In addition, the 2001 NHTS has been augmented with land use variables in the form of densities of population and residences at the census tract and block level for each of the more than 69,000 households in the dataset. In order to obtain unbiased estimates of the effects of any of these land use variables on annual VMT and fuel consumption the authors present a model system that accounts for both self selection effects and missing data that are related to the endogenous variables.

Results for the State of California show that the residential density effects are substantial and precisely estimated. Comparing two households that are similar in all respects except residential density, a lower density of 1,000 housing units per square mile implies a positive difference of almost 1,200 miles per year and about 65 more gallons of fuel per household. This total effect of residential density on fuel usage is decomposed into to two paths of influence. Increased mileage leads to a difference of 45 gallons, but there is an additional direct effect of density through lower fleet fuel economy of 20 gallons per year, a result of vehicle type choice.

working paper

Estimation of Vehicular Emissions by Capturing Traffic Variations

Publication Date

December 31, 2004

Author(s)

Nesamani Kalandiyur, Lianyu Chu, Michael McNally, R. (Jay) Jayakrishnan

Areas of Expertise

Infrastructure Delivery, Operations, & Resilience Zero-Emission Vehicles & Low-Carbon Fuels

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Abstract

Increase in traffic volumes and changes in travel-related characteristics increase vehicular emissions significantly. It is difficult, however, to accurately estimate emissions with current practice because of the reliance on travel forecasting models that are based on steady state hourly averages and, thus, are incapable of capturing the effects of traffic variations in the transportation network. This paper proposes an intermediate model component that can provide better estimates of link speeds by considering a set of Emission Specific Characteristics (ESC) for each link. The intermediate model is developed using multiple linear regression; it is then calibrated, validated, and evaluated using a microscopic traffic simulation model. The improved link speed data can then be used to provide better estimates of emissions. The evaluation results show that the proposed emission estimation method performs better than current practice and is capable of estimating time-dependent emissions if traffic sensor data are available as model input.