Transportation Commons^™

Implications Of Alternative Communications And Sensing Technologies For Implementing Variable Speed Limit Control Through Connected Vehicles: Sag Curve As A Case Study, Reza Vatani Nezafat, Mecit Cetin, Elizabeth Williams, George F. List

Civil & Environmental Engineering Faculty Publications

Connected vehicles (CVs) will enable various applications to improve traffic flow. This paper's focus is to investigate how the potential implementation of variable speed limit (VSL) through different types of communication and sensing technologies on CVs makes it possible to mitigate congestion at a sag curve bottleneck. A VSL algorithm is developed and implemented in a simulation environment for controlling the inflow of vehicles to a sag curve to minimize delays and increase throughput. Both vehicle-to-vehicle (V2V) and infrastructure-to-vehicle (I2V) options for CVs are investigated when implementing the VSL control strategy in a simulation environment. Also, for measuring traffic density …

Attention-Based Data Analytic Models For Traffic Flow Predictions, Kaushal Kumar, Yupeng Wei

Mineta Transportation Institute

Traffic congestion causes Americans to lose millions of hours and dollars each year. In fact, 1.9 billion gallons of fuel are wasted each year due to traffic congestion, and each hour stuck in traffic costs about $21 in wasted time and fuel. The traffic congestion can be caused by various factors, such as bottlenecks, traffic incidents, bad weather, work zones, poor traffic signal timing, and special events. One key step to addressing traffic congestion and identifying its root cause is an accurate prediction of traffic flow. Accurate traffic flow prediction is also important for the successful deployment of smart transportation …

Network Effects Of Disruptive Traffic Events, Juan Medina, Xiaoyue Cathy Liu

TREC Final Reports

Current traffic management strategies are based on expected conditions caused by recurring congestion (e.g., by time of day, day of week), and can be very effective when provisions are also given for reasonable variations from such expectations. However, traffic variations due to non-recurrent events (e.g., crashes) can be much larger and difficult to predict, making also challenging efforts to identify, measure, and forecast their disruptive effects. This project explores a proactive approach to deploy a tool for managing non-recurrent congestion by identifying and quantifying the effects of disruptive traffic events at a microscopic level using a comprehensive set of data …

Assessing Public Health Benefits Of Replacing Freight Trucks With Cargo Cycles In Last Leg Delivery Trips In Urban Centers, Jennifer C. Hartle, Ossama (Sam) A. Elrahman, Cara Wang, Daniel A. Rodriguez, Yue Ding, Matt Mcgahan

Mineta Transportation Institute

Increased urbanization, population growth, and demand for time-sensitive deliveries means increased freight movement in cities, which contributes to emissions, noise, and safety concerns. One innovative mode gaining widespread attention for urban deliveries is cargo cycles—bicycles adapted for freight delivery. Despite the recognized potential and possible success of transporting at least 25% of freight via cycle, research remains limited. This research investigates the potential of cargo cycle delivery for last mile freight in Oakland, California, with a focus on the West Oakland neighborhood. The data collection included interviews, focus groups, vehicle field observation and counts, and traffic simulation modeling. The traffic …

Congestion Costs And Scheduling Preferences Of Car Commuters In California: Estimates Using Big Data, Jinwon Kim, Jucheol Moon

Mineta Transportation Institute

On average, California car commuters waste 4–5 minutes per morning commute due to congestion. Multiplied across all California car commuters, those few minutes entail a yearly total of approximately 2.3 billion hours of time wasted, costing 6 billion dollars. The objective of this study is to quantify congestion costs and determine how commuters adapt to the level of congestion they face (i.e., commuters’ scheduling utility functions). To that end, this research developed a model of trip scheduling under congestion to construct California commuters’ travel-time profiles, i.e., the menu of travel times that each individual would likely face according to alternate …

Vehicular Crowdsourcing For Congestion Support In Smart Cities, Stephan Olariu

Computer Science Faculty Publications

Under present-day practices, the vehicles on our roadways and city streets are mere spectators that witness traffic-related events without being able to participate in the mitigation of their effect. This paper lays the theoretical foundations of a framework for harnessing the on-board computational resources in vehicles stuck in urban congestion in order to assist transportation agencies with preventing or dissipating congestion through large-scale signal re-timing. Our framework is called VACCS: Vehicular Crowdsourcing for Congestion Support in Smart Cities. What makes this framework unique is that we suggest that in such situations the vehicles have the potential to cooperate with various …

Online Traffic Signal Control Through Sample-Based Constrained Optimization, Srishti Dhamija, Alolika Gon, Pradeep Varakantham, William Yeoh

Research Collection School Of Computing and Information Systems

Traffic congestion reduces productivity of individuals by increasing time spent in traffic and also increases pollution. To reduce traffic congestion by better handling dynamic traffic patterns, recent work has focused on online traffic signal control. Typically, the objective in traffic signal control is to minimize expected delay over all vehicles given the uncertainty associated with the vehicle turn movements at intersections. In order to ensure responsiveness in decision making, a typical approach is to compute a schedule that minimizes the delay for the expected scenario of vehicle movements instead of minimizing expected delay over the feasible vehicle movement scenarios. Such …

Do Transportation Network Companies Decrease Or Increase Congestion?, Gregory D. Erhardt, Sneha Roy, Drew Cooper, Bhargava Sana, Mei Chen, Joe Castiglione

Civil Engineering Faculty Publications

This research examines whether transportation network companies (TNCs), such as Uber and Lyft, live up to their stated vision of reducing congestion in major cities. Existing research has produced conflicting results and has been hampered by a lack of data. Using data scraped from the application programming interfaces of two TNCs, combined with observed travel time data, we find that contrary to their vision, TNCs are the biggest contributor to growing traffic congestion in San Francisco. Between 2010 and 2016, weekday vehicle hours of delay increased by 62% compared to 22% in a counterfactual 2016 scenario without TNCs. The findings …

Traffic Signal Consensus Control, Gerardo Lafferriere

TREC Final Reports

We introduce a model for traffic signal management based on network consensus control principles. The underlying principle in a consensus approach is that traffic signal cycles are adjusted in a distributed way so as to achieve desirable ratios of queue lengths throughout the street network. This approach tends to reduce traffic congestion due to queue saturation at any particular city block and it appears less susceptible to congestion due to unexpected traffic loads on the street grid. We developed simulation tools based on the MATLAB computing environment to analyze the use of the mathematical consensus approach to manage the signal …

Traffic-Cascade: Mining And Visualizing Lifecycles Of Traffic Congestion Events Using Public Bus Trajectories, Agus Trisnajaya Kwee, Meng-Fen Chiang, Philips Kokoh Prasetyo, Ee-Peng Lim

Research Collection School Of Computing and Information Systems

As road transportation supports both economic and social activities in developed cities, it is important to maintain smooth traffic on all highways and local roads. Whenever possible, traffic congestions should be detected early and resolved quickly. While existing traffic monitoring dashboard systems have been put in place in many cities, these systems require high-cost vehicle speed monitoring instruments and detect traffic congestion as independent events. There is a lack of low-cost dashboards to inspect and analyze the lifecycle of traffic congestion which is critical in assessing the overall impact of congestion, determining the possible the source(s) of congestion and its …

Life In Hampton Roads Survey Press Release #4: Transportation, Social Science Research Center, Old Dominion University

Life in Hampton Roads Survey Report

This report examines regional perceptions of transportation related issues from the 2017 Life In Hampton Roads survey (LIHR 2017) conducted by the Old Dominion University Social Science Research Center. Data from prior years is also provided when available to show comparisons in responses over time. Responses were weighted by city population, race, age, gender, and phone usage (cell versus land-line) to be representative of the Hampton Roads region.

Life In Hampton Roads Survey Press Release #4: Transportation, Social Science Research Center, Old Dominion University

Life in Hampton Roads Survey Report

This report examines regional perceptions of transportation related issues from the 2016 Life In Hampton Roads survey (LIHR 2016) conducted by the Old Dominion University Social Science Research Center. Data from prior years is also provided when available to show comparisons in responses over time. Responses were weighted by city population, race, age, gender, and phone usage (cell versus land-line) to be representative of the Hampton Roads region.

Utilizing High Resolution Bus Gps Data To Visualize And Identify Congestion Hot-Spots In Urban, Nicholas B. Stoll, Travis B. Glick, Miguel Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Congestion and travel delay on urban roadways can influence the roadways’ operating costs and service attractiveness. This research used high-resolution bus data to examine sources of delay on urban arterials. A set of tools was created to help visualize trends in bus behavior and movement; these tools allowed larger traffic trends to be visualized along urban corridors and streets. With buses as probes and examining aggregated bus behavior, contoured speed plots were used to understand the behavior of roadways outside the zone of influence of bus stops. Speed plots were used to discover trends and travel patterns with only a …

Analyzing Driver Behavior And Traffic Flow Breakdowns At The Hampton Roads Bridge Tunnel, Michelle L. Allen

Civil & Environmental Engineering Theses & Dissertations

The Hampton Roads Bridge Tunnel (HRBT) is a major link for activity in Hampton Roads. The eastbound direction also suffers from congestion during both morning and peak hours. During these periods of congestion, the flow rate varies in regards to the location of the congestion. This study focuses on investigating driver behavior during these different conditions and briefly investigates the cost of delay due to the different capacities. To accomplish this, per vehicle record data (PVR) is used. This data, collected at the exit of the tunnel, provides information on arrival time, speed, lane location, vehicle class, and time headway. …

Life In Hampton Roads Survey Press Release #4: Transportation, Social Science Research Center, Old Dominion University

Life in Hampton Roads Survey Report

This report examines regional and sub-regional perceptions of transportation related issues from the 2015 Life In Hampton Roads survey (LIHR 2015) conducted by the Old Dominion University Social Science Research Center. Data from prior years is also provided when available to show comparisons in responses over time. Responses were weighted by city population, race, age, gender, and phone usage (cell versus land-line) to be representative of the Hampton Roads region.

A Comparative Study: Utilizing Data Mining Techniques To Classify Traffic Congestion Status, Abbas Mirakhorli

UNLV Theses, Dissertations, Professional Papers, and Capstones

Performance measure is a process of evaluating and quantifying a system. Performance measure provides us with information about how good a system is working and how well the predefined goals are met. In order to analyze the performance of a transportation system, the traffic data such as speed, volume, occupancy and travel time of the system need to be collected. These data will generate valuable historical database that can be used to develop models to improve the quality of service of transportation system. The performance measures in transportation studies can be categorized to following main groups: Congestion, Mobility, Accessibility, Reliability, …

Managing Private Vehicles In Asian Cities, Sock-Yong Phang

Research Collection School Of Economics

Asia's rapid urbanization and growing incomes have resulted in a corresponding booming market in motor vehicle sales. In 2013, an estimated 18 million new passenger cars were sold in China. Motor vehicle users generate congestion, pollution, accidents, noise and road damage. Yet, in most cities motor vehicle users often do not pay the full social costs and are therefore implicitly subsidized by non-users. According to the Tom Tom Traffic Index, which is based on GPS data, motorists in the worst congested cities in developed countries spend up to 40% more time for peak hour commutes. This level of delay is …

The Fundamental Law Of Highway Congestion Revisited: Evidence From National Expressways In Japan, Wen-Tai Hsu, Hongliang Zhang

Research Collection School Of Economics

The fundamental law of highway congestion states that when congested, the travel speed on an expanded expressway reverts to its previous level before the capacity expansion. In this paper, we propose a theory that generalizes this statement and finds that if there exists a coverage effect, that is, the effect of longer road length on traffic conditional on capacity, then the new equilibrium travel speed could be lower than its previous level. Given the fundamental law, the theory predicts that the elasticity of traffic to road capacity is at least 1. We estimate this elasticity for national expressways in Japan …

Life In Hampton Roads Survey Press Release #4: The Changing Transportation Picture: Tolls And Traffic, Social Science Research Center, Old Dominion University

Life in Hampton Roads Survey Report

This report examines regional and sub-regional measures of transportation perceptions from the 2014 Life In Hampton Roads survey (LIHR 2014) conducted by the Old Dominion University Social Science Research Center.

Impact Of Rail Transit On The Denver Metro Region: Transportation And Land Use, Sutapa Bhattacharjee

Electronic Theses and Dissertations

Among the reasons behind construction of the light rail system in the 1990s and 2000s and currently the FasTracks lines, in Denver metro region, has been reduction of traffic congestion and consolidation of land use. This research analyzes the success of the rail transit system in achieving the above-mentioned goals.

A temporal and spatial analysis of Vehicle Miles Traveled (VMT) data from 1992 to 2008 on the highways in Denver has been conducted to determine if traffic congestion has reduced after the initial light rail service began in 1994. Temporal analysis provides an insight into the changes in the level …

Demand Responsive Signal Control Strategy (Drsc) Incorporating Queue Length Information In Real-Time Signal Control, Rahul Rajbhara

Civil & Environmental Engineering Theses & Dissertations

Most of the existing vehicle detection systems, namely inductive loops, video cameras etc. are incapable of measuring the queue lengths at signalized intersections. However, with the advent of modern technology, newer detection methods such as probe vehicles equipped with wireless communications (Connected Vehicles), particularly under the Vehicle Infrastructure Integration [52), and radar detection currently provide this capability [53). This thesis presents a Demand Responsive Signal Control Strategy (termed as DRSC) for an isolated signalized intersection. The control strategy incorporates real-time queue length information (obtained from probe vehicles) into the signal control logic. Demand based maximum green time for each upcoming/new …

Integrating Probe Vehicles And Stationary Detector Data To Construct Accurate Cumulative Curves To Study Bottlenecks, Khairul Azfi Anuar

Civil & Environmental Engineering Theses & Dissertations

Advancements in sensors technologies have given researchers and practitioners access to an immense amount of traffic data from multiple types of sensors. However, because of the diversity of the data types, developing a relationship between the different data sources can be challenging. To further complicate the issue, the presence of error or noise makes it difficult to infer any reliable conclusions from the data. To develop a relationship between different data sources, a new methodology is proposed in this thesis for fusing stationary detector data and probe vehicle data to construct an accurate cumulative curve. To remove or to reduce …

Exploring The Effects Of Cooperative Adaptive Cruise Control In Mitigating Traffic Congestion, Georges M. Arnaout

Engineering Management & Systems Engineering Theses & Dissertations

The aim of this research is to examine the impact of CACC (Cooperative Adaptive Cruise Control) equipped vehicles on traffic-flow characteristics of a multilane highway system. The research identifies how CACC vehicles affect the dynamics of traffic flow on a road network and demonstrates the potential benefits of reducing traffic congestion due to stop-and-go traffic conditions. An agent-based traffic simulation model is developed specifically to examine the effect of these intelligent vehicles on the traffic flow dynamics. Traffic performance metrics characterizing the evolution of traffic congestion throughout the road network, are analyzed. Different CACC penetration levels are studied.

The positive …

Freight Distribution Problems In Congested Urban Areas: Fast And Effective Solution Procedures To Time-Dependent Vehicle Routing Problems, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Congestion is a common phenomenon in all medium to large cities of the world. Reliability of freight movement in urban areas is an important issue to manufacturing or service companies whose operation is based in just-in-time approaches. These companies tend to provide high value or time sensitive products/services. As congestion increases, carriers face increasing challenges to satisfy their time sensitive customers in an economical way. Route designs or schedules which require long computation times or ignore travel time variations will result in inefficient and suboptimal solutions. Poorly designed routes that lead freight vehicles into congested arteries and streets not only …

Light-Rail In Louisville: Assessing The Financial Feasibility Of Mass Transit, Brian K. Howell

MPA/MPP/MPFM Capstone Projects

The Louisville-Jefferson County area encompasses a vast area and large population of citizens. To meet the transportation needs of this growing city, the Transit Authority of River City or TARC undertook a study in 1996 to determine potential transportation solutions to traffic congestion in the area. Based on their analysis, TARC determined that a 15-mile light rail transit system would best service their needs. This light rail system would run from the downtown central business district to a park-and-ride facility at the Gene Snyder Freeway.

Prior to undertaking this project, TARC and all those parties involved should ask the fundamental …

Road Congestion Pricing In Singapore: 1975-2003, Sock-Yong Phang, Rex S. Toh

Research Collection School Of Economics

Facing traffic congestion in the Central Business District and enormous demands on scarce land resources by the growing number of motor vehicles, Singapore, a small island city-state the size of Seattle, embarked on a bold decision to reduce road congestion by implementing the famous Area Licensing Scheme in 1975. This was a manual system of tolls for multiple entries into the Restricted Zone. While achieving the intended effect of cutting down on the volume of vehicular traffic in the Restricted Zone, the authors (and others) found that the problem of congestion had merely shifted in time and place. Many changes …

Multiple Convergence: Induced Travel Analysis In Metropolitan Areas, Jihong Zhang

Dissertations and Theses

The triple convergence principle, proposed by Anthony Downs, states that subsequent to increases in roadway supply, travelers change their travel route, time, and mode to mitigate the effect of lowering congestion levels. More recently, studies indicate that building roadways also induces people to drive more, a phenomenon called induced travel.

Using personal data from the 1995 Nationwide Personal Transportation Survey (NPTS) enriched with roadway supply data from the Texas Transportation Institute (TTI), this dissertation studies travel behavioral responses of urban workers to roadway supply improvements. These responses include the possible additional travel amount as well as the spatial, temporal and …

Isolated Ramp Metering Feedback Control Utilizing Mixed Sensitivity For Desired Mainline Density And The Ramp Queues, Pushkin Kachroo, Kaan Ozbay, Donald E. Grove

Electrical & Computer Engineering Faculty Research

This paper presents a feedback control design for isolated ramp metering control. This feedback control design, unlike the existing isolated feedback ramp controllers, also takes into account the ramp queue length. Using a nonlinear H∞ control design methodology, we formulate the problem in the desired setting to be able to utilize the results of the methodology.

Incident Management In Intelligent Transportation Systems, Kaan Ozbay, Pushkin Kachroo

Electrical & Computer Engineering Faculty Research

Since the conception of Intelligent Transportation Systems (ITS) in the 1980s, many transportation researchers have also worked on the development of incident management models and integrated systems for real-time operations. ITS created the required infrastructure for collecting, processing, and managing real-time traffic data that can be used to develop on-line incident management strategies. This book provides the reader with a broad picture of the overall incident management process in the context of ITS along with a quick review of the models and systems developed by numerous researchers worldwide. This book is a direct result of the long-term incident management research …

From Manual To Electronic Road Congestion Pricing: The Singapore Experience And Experiment, Sock-Yong Phang, Rex S. Toh

Research Collection School Of Economics

This study reviews the efforts of Singapore to curb road congestion through restraints on motor vehicle ownership as well as user fees. In particular, it traces the history of the famous Area Licensing Scheme (ALS), and then discusses its shortcomings, also the need for Electronic Road Pricing (ERP), its advantages and disadvantages and the technology involved in this state of the art system. This paper identifies important research questions to be addressed in connection with the first full-scale adoption of ERP.