Henry Lieu - Academia.edu (original) (raw)

Papers by Henry Lieu

Research paper thumbnail of Traffic Estimating and Predicting Takes a Positive Turn with Dta

This article describes the development of a deployable real-time Dynamic Traffic Assignment (DTA)... more This article describes the development of a deployable real-time Dynamic Traffic Assignment (DTA) system. A DTA system is defined as having the following capabilities: 1) estimating and predicting traffic roadway conditions; 2) providing advisory traffic information through Advanced Traveler Information Systems (ATIS); and, 3) interfacing with Advanced Traffic Management Systems (ATMS) and Advanced Traveler Information Systems. It also reports on two efforts towards the development of a prototype DTA system demonstrating its potential for real-time application capability.

Research paper thumbnail of Corsim - a State-Of-The-Best Practice for Traffic Operation Analysis

This article briefly describes the first Windows-based version of a traffic simulation model. Kno... more This article briefly describes the first Windows-based version of a traffic simulation model. Known as CORSIM, and integrating existing NETSIM and FRESIM models, this microscopic, stochastic traffic simulation model can realistically represent the real world dynamic traffic environment. CORSIM has the most sophisticated car-following and lane-changing logic to simulate vehicle movements on a second-by- second basis.

Research paper thumbnail of Benefit Assessment of Implementing Weather-Specific Signal Timing Plans by Using CORSIM

Transportation Research Record: Journal of the Transportation Research Board, 2004

The effect of weather on the nation's surface transportation systems touches people every day... more The effect of weather on the nation's surface transportation systems touches people every day. Each year 7,000 fatalities and 800,000 injuries involve weather-related adverse road conditions as a factor. These statistics represent about 28% of all highway crashes and 19% of all fatalities. The estimated annual economic cost due to weather-related crashes (deaths, injuries, and property) amounts to nearly $42 billion. Adverse weather has a significant impact on traffic operations and is a challenging issue to traffic engineers. However, there is a perception that traffic engineers can do little to mitigate the effects of weather, which is the result of two main factors: (a) no specific tools are currently available for traffic engineers to assess weather impacts on traffic operations and (b) both traffic and weather data are lacking for traffic analyses. As a result, traffic engineers have little understanding of traffic behaviors due to loss of visibility and traction in bad weather. As more road weather information systems and intelligent transportation systems are deployed and integrated, a large amount of traffic and weather data will become available. Data availability and powerful traffic simulation tools make it possible for engineers to develop and assess weather-specific traffic operations strategies to mitigate congestion in bad weather. The purpose of this study is to use CORSIM (a microscopic traffic simulation model) to illustrate a procedure for assessing benefits of retiming traffic signals in bad weather for both principal arterials and regional networks. Some preliminary findings and gaps identified for further research are also provided.

Research paper thumbnail of Laboratory evaluation of dynamic traffic assignment systems: Requirements, framework, and system design

PsycEXTRA Dataset

This report was prepared as an account of work sponsored by an agency of the United States Govern... more This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference h m i n to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, mommendbtion, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect thosc of the United States Government or any agency thereof. DISCLAIMER Portions of this document may be illegible in electronic image products. b a g s are produced from the best available original document.

Research paper thumbnail of Beyond the Highway Capacity Manual Framework for Selecting Simulation Models in Traffic Operational Analyses

Transportation Research Record: Journal of the Transportation Research Board, 1999

Simulation is often used to address issues that cannot be effectively resolved using the Highway ... more Simulation is often used to address issues that cannot be effectively resolved using the Highway Capacity Manual (HCM) or other analytical procedures. However, guidelines are not available for appropriate application of simulation as a complement or substitute for HCM procedures. The purpose of this paper is threefold: ( a) to provide an overview of simulation models in a context consistent with facilities and situations addressed by the HCM, ( b) to present a framework for the appropriate selection of simulation models when procedures of the HCM are not adequate, and ( c) to provide brief examples demonstrating application of the proposed framework. The paper is divided into five sections. The first section presents simulation concepts and definitions. The second presents a suggested framework for application of simulation within an HCM context. The third and fourth sections apply this framework to the evaluation of uninterrupted- and interrupted-flow facilities, respectively. In t...

Research paper thumbnail of Real-Time Incident-Responsive System for Corridor Control: Modeling Framework and Preliminary Results

Transportation Research Record, 1994

Research paper thumbnail of Laboratory Evaluation of Real-Time Dynamic Traffic Assignment Systems

Computer-Aided Civil and Infrastructure Engineering, 1999

Research paper thumbnail of The Physics of Traffic: Empirical Freeway Pattern Features, Engineering Applications, and Theory

Physics Today, 2005

... three main goals: First, to elaborate the concepts, methods and tools of self-organizing dyna... more ... three main goals: First, to elaborate the concepts, methods and tools of self-organizing dynamical systems ... 399 16.1 Introduction 399 16.2 Cellular Automata Approach to Three-Phase Traffic Theory . ... in Cellular Automata Models 405 16.2.5 Boundary Conditions and Model of On ...

Research paper thumbnail of The Urban Planning and Development division wishes to thank the following people who reviewed papers submitted to the Journal during the period of August 1, 2006, to July 21, 2007. Jamal Abed Samih Al Rawashdeh Adjo A. Amekudzi

... S. Ali Abbasi. Yasuo Asadura. Yvan J. Beliveau. Michael GH Bell. Salah Benabdallah. John A. B... more ... S. Ali Abbasi. Yasuo Asadura. Yvan J. Beliveau. Michael GH Bell. Salah Benabdallah. John A. Black. Robert L. Cangelosi Jr. Avishi Ceder. ... Becky KY Loo. Yiu-kwan James Luk. Barry Lundberg. Richard Lyles. Roger Laurance Mackett. William A. Moser. Larry Mugler. Sashi Nambisan ...

Research paper thumbnail of Traffic Estimating and Predicting Takes a Positive Turn with Dta

This article describes the development of a deployable real-time Dynamic Traffic Assignment (DTA)... more This article describes the development of a deployable real-time Dynamic Traffic Assignment (DTA) system. A DTA system is defined as having the following capabilities: 1) estimating and predicting traffic roadway conditions; 2) providing advisory traffic information through Advanced Traveler Information Systems (ATIS); and, 3) interfacing with Advanced Traffic Management Systems (ATMS) and Advanced Traveler Information Systems. It also reports on two efforts towards the development of a prototype DTA system demonstrating its potential for real-time application capability.

Research paper thumbnail of Corsim - a State-Of-The-Best Practice for Traffic Operation Analysis

This article briefly describes the first Windows-based version of a traffic simulation model. Kno... more This article briefly describes the first Windows-based version of a traffic simulation model. Known as CORSIM, and integrating existing NETSIM and FRESIM models, this microscopic, stochastic traffic simulation model can realistically represent the real world dynamic traffic environment. CORSIM has the most sophisticated car-following and lane-changing logic to simulate vehicle movements on a second-by- second basis.

Research paper thumbnail of Benefit Assessment of Implementing Weather-Specific Signal Timing Plans by Using CORSIM

Transportation Research Record: Journal of the Transportation Research Board, 2004

The effect of weather on the nation's surface transportation systems touches people every day... more The effect of weather on the nation's surface transportation systems touches people every day. Each year 7,000 fatalities and 800,000 injuries involve weather-related adverse road conditions as a factor. These statistics represent about 28% of all highway crashes and 19% of all fatalities. The estimated annual economic cost due to weather-related crashes (deaths, injuries, and property) amounts to nearly $42 billion. Adverse weather has a significant impact on traffic operations and is a challenging issue to traffic engineers. However, there is a perception that traffic engineers can do little to mitigate the effects of weather, which is the result of two main factors: (a) no specific tools are currently available for traffic engineers to assess weather impacts on traffic operations and (b) both traffic and weather data are lacking for traffic analyses. As a result, traffic engineers have little understanding of traffic behaviors due to loss of visibility and traction in bad weather. As more road weather information systems and intelligent transportation systems are deployed and integrated, a large amount of traffic and weather data will become available. Data availability and powerful traffic simulation tools make it possible for engineers to develop and assess weather-specific traffic operations strategies to mitigate congestion in bad weather. The purpose of this study is to use CORSIM (a microscopic traffic simulation model) to illustrate a procedure for assessing benefits of retiming traffic signals in bad weather for both principal arterials and regional networks. Some preliminary findings and gaps identified for further research are also provided.

Research paper thumbnail of Laboratory evaluation of dynamic traffic assignment systems: Requirements, framework, and system design

PsycEXTRA Dataset

This report was prepared as an account of work sponsored by an agency of the United States Govern... more This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference h m i n to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, mommendbtion, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect thosc of the United States Government or any agency thereof. DISCLAIMER Portions of this document may be illegible in electronic image products. b a g s are produced from the best available original document.

Research paper thumbnail of Beyond the Highway Capacity Manual Framework for Selecting Simulation Models in Traffic Operational Analyses

Transportation Research Record: Journal of the Transportation Research Board, 1999

Simulation is often used to address issues that cannot be effectively resolved using the Highway ... more Simulation is often used to address issues that cannot be effectively resolved using the Highway Capacity Manual (HCM) or other analytical procedures. However, guidelines are not available for appropriate application of simulation as a complement or substitute for HCM procedures. The purpose of this paper is threefold: ( a) to provide an overview of simulation models in a context consistent with facilities and situations addressed by the HCM, ( b) to present a framework for the appropriate selection of simulation models when procedures of the HCM are not adequate, and ( c) to provide brief examples demonstrating application of the proposed framework. The paper is divided into five sections. The first section presents simulation concepts and definitions. The second presents a suggested framework for application of simulation within an HCM context. The third and fourth sections apply this framework to the evaluation of uninterrupted- and interrupted-flow facilities, respectively. In t...

Research paper thumbnail of Real-Time Incident-Responsive System for Corridor Control: Modeling Framework and Preliminary Results

Transportation Research Record, 1994

Research paper thumbnail of Laboratory Evaluation of Real-Time Dynamic Traffic Assignment Systems

Computer-Aided Civil and Infrastructure Engineering, 1999

Research paper thumbnail of The Physics of Traffic: Empirical Freeway Pattern Features, Engineering Applications, and Theory

Physics Today, 2005

... three main goals: First, to elaborate the concepts, methods and tools of self-organizing dyna... more ... three main goals: First, to elaborate the concepts, methods and tools of self-organizing dynamical systems ... 399 16.1 Introduction 399 16.2 Cellular Automata Approach to Three-Phase Traffic Theory . ... in Cellular Automata Models 405 16.2.5 Boundary Conditions and Model of On ...

Research paper thumbnail of The Urban Planning and Development division wishes to thank the following people who reviewed papers submitted to the Journal during the period of August 1, 2006, to July 21, 2007. Jamal Abed Samih Al Rawashdeh Adjo A. Amekudzi

... S. Ali Abbasi. Yasuo Asadura. Yvan J. Beliveau. Michael GH Bell. Salah Benabdallah. John A. B... more ... S. Ali Abbasi. Yasuo Asadura. Yvan J. Beliveau. Michael GH Bell. Salah Benabdallah. John A. Black. Robert L. Cangelosi Jr. Avishi Ceder. ... Becky KY Loo. Yiu-kwan James Luk. Barry Lundberg. Richard Lyles. Roger Laurance Mackett. William A. Moser. Larry Mugler. Sashi Nambisan ...