Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

PDF

2010

University of Massachusetts Amherst

Daiheng Ni

Articles 1 - 5 of 5

Full-Text Articles in Engineering

The Effect Of Intellidrive On The Efficiency Of Highway Transportation Systems, Mohammad Nekoui, Hossein Pishro-Nik, Daiheng Ni Dec 2010

The Effect Of Intellidrive On The Efficiency Of Highway Transportation Systems, Mohammad Nekoui, Hossein Pishro-Nik, Daiheng Ni

Daiheng Ni

Recently, the IntelliDrive initiative has been proposed by the US Department of Transportation (USDOT) to enhance on-road safety and efficiency. In this study, we provide a mathematical framework which predicts the effect of such technologies on the efficiency of multilane highway systems prior to their real-life deployment. Our study shall encompass mixed traffic conditions in which a variety of assisted, automated and unequipped vehicles coexist. We show that intervehicular communications improves the flow of vehicles by reducing the perception-reaction (P-R) times of drivers and, in some cases, allowing for more efficient lane-changing operations. As we shall see, unlike the latter, …


A Spectrum Of Traffic Flow Modeling At Multiple Scales, Daiheng Ni Dec 2010

A Spectrum Of Traffic Flow Modeling At Multiple Scales, Daiheng Ni

Daiheng Ni

his paper presents a broad perspective on traffic flow modeling at a spectrum of four scales. Modeling objectives and model properties at each scale are discussed and existing efforts are reviewed. In order to ensure modeling consistency and provide a microscopic basis for macroscopic models, it is critical to address the coupling among models at different scales, i.e. how less detailed models are derived from more detailed models and, conversely, how more detailed models are aggregated to less detailed models. With this understanding, a consistent modeling approach is proposed based on field theory and modeling strategies at each of the …


Preliminary Estimate Of Highway Capacity Benefit Attainable With Intellidrive Technologies, Daiheng Ni, Jia Li, Steven Andrews, Haizhong Wang Sep 2010

Preliminary Estimate Of Highway Capacity Benefit Attainable With Intellidrive Technologies, Daiheng Ni, Jia Li, Steven Andrews, Haizhong Wang

Daiheng Ni

Recent development in IntelliDrive and associated Vehicular Ad Hoc Networks (VANET) has stimulated tremendous interests among decision-makers, practitioners, and researchers due to the potential safety and mobility benefits provided by these technologies. A primary concern regarding the deployment of IntelliDrive is degree of market penetration required for effectiveness. This paper proposes an approach to analyze the benefit of highway capacity gained from IntelliDrive. To fulfill this purpose, a model incorporating the effects of IntelliDrive on car following is formulated, based on which a rough estimate of the resulting capacity gain is derived. A simulation study is conducted to verify the …


Scenario-Based Analysis Of Transportation Impacts In Case Of Dam Failure Flood Evacuation In Franklin County, Massachusetts (Paper # 10-1352), Haizhong Wang, Steven Andrews, John Collura, Daiheng Ni Jan 2010

Scenario-Based Analysis Of Transportation Impacts In Case Of Dam Failure Flood Evacuation In Franklin County, Massachusetts (Paper # 10-1352), Haizhong Wang, Steven Andrews, John Collura, Daiheng Ni

Daiheng Ni

Emergency planning is an important practice that allows government officials and planners to prepare for disasters and to make prompt response s that can save lives and property . One of the foremost concern s during an emergency is to save as many lives as possible. Thus, whethe r people can leave the disaster areas safely and efficiently is a prime consideration in emergency planning and management. Usually, transportation planners use a four - step model to predict sy s- tem - level performance regarding how people move from on e place to another , and to determine the network …


Representing The Fundamental Diagram: The Pursuit Of Mathematical Elegance And Empirical Accuracy (Paper # 10-1354), Haizhong Wang, Jia Li, Qian-Yong Chen, Daiheng Ni Jan 2010

Representing The Fundamental Diagram: The Pursuit Of Mathematical Elegance And Empirical Accuracy (Paper # 10-1354), Haizhong Wang, Jia Li, Qian-Yong Chen, Daiheng Ni

Daiheng Ni

The fundamental diagram, as the graphical representation of the relationships among traffic flow, speed, and density, has been the foundation of traffic flow theory and transportation engineering. 75 years after the seminal Greenshields model, a variety of models have been proposed to mathematically represent the speed-density relationship which underlies the fundamental diagram. Observed in these models was a clear path toward two competing goals: mathematical elegance and empirical accuracy. As the latest development of such a pursuit, this paper presents a family of speed-density models with varying numbers of parameters. All of these models perform satisfactorily and have physically meaningful …