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Articles 481 - 510 of 744

Full-Text Articles in Transportation

Designing Bus Transit Services For Routine Crowd Situations At Large Event Venues, Jianli Du, Shih-Fen Cheng, Hoong Chuin Lau Sep 2015

Designing Bus Transit Services For Routine Crowd Situations At Large Event Venues, Jianli Du, Shih-Fen Cheng, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

We are concerned with the routine crowd management problem after a major event at a known venue. Without properly design complementary transport services, such sudden crowd build-ups will overwhelm the existing infrastructure. In this paper, we introduce a novel flow-rate based model to model the dynamic movement of passengers over the transportation flow network. Based on this basic model, an integer linear programming model is proposed to solve the bus transit problem permanently. We validate our model against a real scenario in Singapore, where a newly constructed mega-stadium hosts various large events regularly. The results show that the proposed approach …


Vessel Tracking Using Automatic Identification System Data In The Arctic, Torkild Eriksen, Øystein Olsen Aug 2015

Vessel Tracking Using Automatic Identification System Data In The Arctic, Torkild Eriksen, Øystein Olsen

ShipArc 2015 Conference

No abstract provided.


Use Of Satellite Sar Observations Integrated In Arctic Maritime Situational Awareness, Hans Eilif Larsen Aug 2015

Use Of Satellite Sar Observations Integrated In Arctic Maritime Situational Awareness, Hans Eilif Larsen

ShipArc 2015 Conference

No abstract provided.


Research On Xiamen Port Network Layout From The Perspective Of Harbors And Inland Ports Linked Development, Yijun Zheng Aug 2015

Research On Xiamen Port Network Layout From The Perspective Of Harbors And Inland Ports Linked Development, Yijun Zheng

World Maritime University Dissertations

No abstract provided.


Improved Safety Performance Functions For Signalized Intersections, Karen Dixon, Christopher Monsere, Raul Avelar, Joel Stephen Barnett, Paty Escobar, Sirisha Murthy Kothuri Aug 2015

Improved Safety Performance Functions For Signalized Intersections, Karen Dixon, Christopher Monsere, Raul Avelar, Joel Stephen Barnett, Paty Escobar, Sirisha Murthy Kothuri

Civil and Environmental Engineering Faculty Publications and Presentations

For this effort, the research team developed new safety performance functions (SPFs) for signalized intersections in Oregon. The modeling dataset consisted of 964 crashes from a total of 73 intersections that were randomly selected based on the presence of a traffic signal (identified through the crash data records). The SPFs were developed using a Poissonlognormal Generalized Linear Mixed model framework for total crashes and severe injury crashes (coded as KAB). Three SPFs were developed: 1) an SPF for total crashes, which relies on both major and minor AADTs to predict the expected number of crashes; 2) an SPF for KAB …


Robust Observability, Control, & Economics Of Complex Cyber-Physical Networks, Shaurya Agarwal Aug 2015

Robust Observability, Control, & Economics Of Complex Cyber-Physical Networks, Shaurya Agarwal

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation deals with various aspects of cyber-physical system. As an example of cyber physical systems, we take transportation networks and solve various problems, namely: 1) Network Observability Problem, 2) Network Control Problem, and 3) Network Economics Problem. We have divided the dissertation into three parts which solve these three problems separately. First part of the dissertation presents a novel approach for studying the observability problem on a general network topology of a traffic network. We develop a new framework which investigates observability in terms of flow information on arcs and the routing information. Second part of the dissertation presents …


Toward A Spatial-Temporal Measure Of Land-Use Mix, Steven R. Gehrke, Kelly Clifton Jul 2015

Toward A Spatial-Temporal Measure Of Land-Use Mix, Steven R. Gehrke, Kelly Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

Urban planning and public-health research has long been interested in the connection between land-use mix and travel. Interest from urban planners stems from the potential of transportation efficiency gains achieved by an increased land-use mix and subsequent shortening of trip lengths; whereas, public-health research advocates an increased land-use mix as an effective policy for facilitating greater physical activity. Yet, despite the transportation, land-use, and health benefits related to improving land-use mix and the extent of topical attention given by researchers, no consensus has been reached regarding the magnitude of its effect on travel. This absence of agreement may largely be …


Development Of A Pedestrian Demand Estimation Tool: A Destination Choice Model, Christopher D. Muhs, Kelly Clifton, Patrick Allen Singleton, Robert J. Schneider May 2015

Development Of A Pedestrian Demand Estimation Tool: A Destination Choice Model, Christopher D. Muhs, Kelly Clifton, Patrick Allen Singleton, Robert J. Schneider

Civil and Environmental Engineering Faculty Publications and Presentations

There is growing support for improvements to the quality of the walking environment, including more investments to promote pedestrian travel. Planners, engineers, and others seek improved tools to estimate pedestrian demand that are sensitive to environmental and demographic factors at the appropriate scale in order to aid policy-relevant issues like air quality, public health, and smart allocation of infrastructure and other resources. Further, in the travel demand forecasting realm, tools of this kind are difficult to implement due to the use of spatial scales of analysis that are oriented towards motorized modes, vast data requirements, and computer processing limitations.

To …


Hiding Private Locations By Anonymizing Data, Kelly J. Clifton, Steven R. Gehrke May 2015

Hiding Private Locations By Anonymizing Data, Kelly J. Clifton, Steven R. Gehrke

TREC Project Briefs

Researchers explore ways of masking private locations in the interest of making useful data publicly available.


Solving Multi-Vehicle Profitable Tour Problem Via Knowledge Adoption In Evolutionary Bi-Level Programming, Stephanus Daniel Handoko, Abhishek Gupta, Chen Kim Heng, Hoong Chuin Lau, Yew Soon Ong, Puay Siew Tan May 2015

Solving Multi-Vehicle Profitable Tour Problem Via Knowledge Adoption In Evolutionary Bi-Level Programming, Stephanus Daniel Handoko, Abhishek Gupta, Chen Kim Heng, Hoong Chuin Lau, Yew Soon Ong, Puay Siew Tan

Research Collection School Of Computing and Information Systems

Profitable tour problem (PTP) belongs to the class of vehicle routing problem (VRP) with profits seeking to maximize the difference between the total collected profit and the total cost incurred. Traditionally, PTP involves single vehicle. In this paper, we consider PTP with multiple vehicles. Unlike the classical VRP that seeks to serve all customers, PTP involves the strategic-level customer selection so as to maximize the total collected profit and the operational-level route optimization to minimize the total cost incurred. Therefore, PTP is essentially the knapsack problem at the strategic level with VRP at the operational level. That means the evolutionary …


Webinar: Impacts Of Roadway And Traffic Characteristics On Air Pollution Risks For Bicyclists, Alexander Y. Bigazzi Apr 2015

Webinar: Impacts Of Roadway And Traffic Characteristics On Air Pollution Risks For Bicyclists, Alexander Y. Bigazzi

TREC Webinar Series

Active travel such as walking and bicycling can lead to health benefits through an increase in physical activity. At the same time, more active travelers breath more and so can experience high pollution inhalation rates during travel. This webinar will review the state of knowledge about how roadway and traffic characteristics impact air pollution risks for bicyclists, including the latest PSU research quantifying bicyclists' uptake of traffic-related air pollution using on-road measurements in Portland. The PSU research team including Alex Bigazzi, Jim Pankow, and Miguel Figliozzi quantified bicyclist exposure concentrations on different types of roadways, respiration responses to exertion level, …


Smarter Cycling, Cory Koehler, Richard Smith, Sarah St. Clair, Alex Taylor, Aubrey Masten, Konon Phillips Apr 2015

Smarter Cycling, Cory Koehler, Richard Smith, Sarah St. Clair, Alex Taylor, Aubrey Masten, Konon Phillips

PSU High School Innovation Challenge

With the current trend of urbanization, the populations of major cities such as Portland are steadily increasing. This is causing a variety of problems, both within the city and in rural areas. In regards to the city, the major challenges facing city planners are the need for the expansion of residential neighborhoods and a rise in traffic throughout the city. One way to tackle the issue of an abundance of traffic, is to make alternate means of transportation more appealing to residents. We chose to focus on bicycling because of the bike‐friendly culture already in place in Portland. An increase …


Analyzing Driver Behavior And Traffic Flow Breakdowns At The Hampton Roads Bridge Tunnel, Michelle L. Allen Apr 2015

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. …


Webinar: Exploring Pedestrian Responsive Traffic Signal Timing Strategies In Urban Areas, Sirisha Murthy Kothuri Jan 2015

Webinar: Exploring Pedestrian Responsive Traffic Signal Timing Strategies In Urban Areas, Sirisha Murthy Kothuri

TREC Webinar Series

The role of walking in the development of healthy, livable communities is being increasingly recognized. In urban areas, intersections are often viewed as a deterrent to walking, as their operation primarily favors automobiles, leading to large and unnecessary delays for pedestrians. There is currently very limited research on accommodating and/or prioritizing pedestrians at signalized intersections in the North American context. Pedestrians are often considered as a deterrent to efficient vehicular traffic flow and therefore active efforts to include them in operational decisions at intersections have been lagging. This research aims to fill that gap by understanding factors that influence pedestrian …


Aerospace Renaissance – Ripe For Research To Impact The Industry, Constantine M. Koursaris, Brig. Gen. Robert E. Mansfield Jr. (Ret.) Jan 2015

Aerospace Renaissance – Ripe For Research To Impact The Industry, Constantine M. Koursaris, Brig. Gen. Robert E. Mansfield Jr. (Ret.)

Aviation / Aeronautics / Aerospace International Research Conference

The Center for Aviation and Aerospace Leadership (CAAL) was founded in 2008 to capture, create, and share relevant information on leadership in the aviation and aerospace industry.

The AIR is developed and published in collaboration with the Aerospace Industries Association and includes:

• Information on the status of aerospace manufacturing in the United States and state of the economy

• An in-depth review of sales across the various sectors of the industry, employment trends, key international trade statistics, financial information on the industry & major aerospace firms, trends to watch, and a forecast for the future based on a review …


Comparing Mode Shares For Non-Residential Destinations In Urban And Suburban Environments, Tasnia Subrin Jan 2015

Comparing Mode Shares For Non-Residential Destinations In Urban And Suburban Environments, Tasnia Subrin

Civil and Environmental Engineering Master's Project Reports

To ensure facility for multimodal transportation is one of the most important concerns in today's transportation sector, with initiatives being taken to make multimodal transportation popular. The built environment variables have a strong relationship with transportation mode choice, but whether that relationship holds true in urban and suburban neighborhoods in the same manner has not been considered. Using data for three non-residential land uses, this research explores whether the built environment variables in suburban areas influences mode share like it does in urban areas. We used survey data conducted at the establishments regarding respondents' travel characteristics from a previous study, …


Crash Frequency Analysis Of Left-Side Merging And Diverging Areas On Urban Freeway Segments: A Case Study Of I-75 Through Downtown Dayton, Ohio, Deogratias Eustace, Aline Aylo, Worku Y. Mergia Jan 2015

Crash Frequency Analysis Of Left-Side Merging And Diverging Areas On Urban Freeway Segments: A Case Study Of I-75 Through Downtown Dayton, Ohio, Deogratias Eustace, Aline Aylo, Worku Y. Mergia

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

This paper analyzes the effect of left- and right-side merging and diverging areas and other variables such as light condition, roadway pavement condition, drivers’ age and presence of construction work zones on the occurrence frequency of crashes. A 6.5-mile (10.5-km) section of I-75 that passes through downtown Dayton, Ohio was considered. The area of interest has a high traffic volume and consists of different geometric design challenges including closely spaced merging and diverging ramps. A four-year record of crash data (2005–2008) and a statistical modeling technique that assumes a negative binomial distribution on generalized linear models (GLMs) were used to …


Road Management System And Road Safety In Uganda, Paul Gudoi Zanule Jan 2015

Road Management System And Road Safety In Uganda, Paul Gudoi Zanule

Walden Dissertations and Doctoral Studies

Traffic collisions cost Uganda millions of dollars each year. The purpose of this descriptive case study was to describe the strategies and processes needed to implement a road management system. Such a system would significantly reduce the fatalities and accidents in Uganda, improve the transportation within Kampala's business district, and increase business profitability. Three conceptual theories framed the research study: management theory, strategic management theory, and criminology theory. Using a snowball sampling strategy, data were collected from open-ended interviews, questionnaires, observations, and archived documents from 20 administrative participants in the government and organizational leaders involved in the transport operations and …


Exploring A Toll Auction Mechanism Enabled By Vehicle-To-Infrastructure Technology, Andrew J. Collins, Erika Frydenlund, R. Michael Robinson, Mecit Cetin Jan 2015

Exploring A Toll Auction Mechanism Enabled By Vehicle-To-Infrastructure Technology, Andrew J. Collins, Erika Frydenlund, R. Michael Robinson, Mecit Cetin

VMASC Publications

High-occupancy toll (HOT) lanes—an increasingly popular solution for congested roadway networks—give drivers the option to access express lanes. The cost of entry often varies with demand, although no standard method of optimizing these price points exists. Using the principles of a Vickrey auction that incentivizes true-value bids, this paper proposes a tolling system that uses vehicle-to-infrastructure technology to optimize toll operator revenue with HOT lane usage. In the scenario, a roadway network consists of a HOT lane and a general-purpose lane, each with identical physical properties. Drivers can access the HOT lane at the start of the facility or at …


A Rapid Approach For Considering Nonlinear Response Of Flexible Pavements Under Fwd And Estimation Of Remaining Lives Of Pavements, Shahabaldin Shirazi Jan 2015

A Rapid Approach For Considering Nonlinear Response Of Flexible Pavements Under Fwd And Estimation Of Remaining Lives Of Pavements, Shahabaldin Shirazi

Open Access Theses & Dissertations

Most mechanistic empirical pavement analyses are based on the layered elastic models where the stress sensitivity of geomaterials and their nonlinearity are either ignored or accounted for indirectly. Advanced numerical models, such as finite element models, are required to consider the nonlinear nature of the geomaterials. Existing pavements are often tested with the Falling Weight Deflectometer (FWD) to estimate the input moduli to the layered elastic models in order to estimate remaining life and structural capacity of pavements. It has been more than 30 years that FWD tests are being performed to measure structural adequacy of pavements. Backcalculation is the …


Adjusting Ite’S Trip Generation Handbook For Urban Context, Kelly J. Clifton, Kristina Marie Currans, Christopher D. Muhs Jan 2015

Adjusting Ite’S Trip Generation Handbook For Urban Context, Kelly J. Clifton, Kristina Marie Currans, Christopher D. Muhs

Civil and Environmental Engineering Faculty Publications and Presentations

This study examines the ways in which urban context affects vehicle trip generation rates across three land uses. An intercept travel survey was administered at 78 establishments (high-turnover restaurants, convenience markets, and drinking places) in the Portland, Oregon, region during 2011. This approach was developed to adjust the Institute of Transportation Engineers (ITE) Trip Generation Handbook vehicle trip rates based on built environment characteristics where the establishments were located. A number of policy-relevant built environment measures were used to estimate a set of nine models predicting an adjustment to ITE trip rates. Each model was estimated as a single measure: …


A Level-Of-Service Model For Protected Bike Lanes, Nick Foster, Christopher Monsere, Jennifer Dill, Kelly Clifton Jan 2015

A Level-Of-Service Model For Protected Bike Lanes, Nick Foster, Christopher Monsere, Jennifer Dill, Kelly Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

Several methods exist for quantifying the quality of service provided by a roadway from a bicyclist’s perspective; however, many of these models do not consider physically protected bike lanes and, of those that do, none is based on empirical data from the US. This is problematic as engineers, planners, and elected officials are increasingly looking to objective performance measures to help guide transportation project design and funding prioritization decisions. This paper addresses this gap by presenting a cumulative logistic model to predict user comfort on protected bike lanes developed from data collected during in-person video surveys. The surveys were conducted …


Can Protected Bike Lanes Help Close The Gender Gap In Cycling? Lessons From Five Cities, Jennifer Dill, Tara Goddard, Christopher Monsere, Nathan Mcneil Nov 2014

Can Protected Bike Lanes Help Close The Gender Gap In Cycling? Lessons From Five Cities, Jennifer Dill, Tara Goddard, Christopher Monsere, Nathan Mcneil

Urban Studies and Planning Faculty Publications and Presentations

Even in areas with increased levels of bicycling, there remains a significant “gender gap” in bicycling in the United States, in contrast to many other countries with high rates of bicycling. The primary objective of this paper was to explore whether protected bike lanes could help reduce the gender gap. To do so, the authors used survey data from a comprehensive evaluation of protected bike lanes in five large U.S. cities (Austin, TX, Chicago, IL, Portland, OR, San Francisco, CA, and Washington, DC) that included survey responses of 1,111 intercepted bicyclists and 2,283 residents. Both men and women overwhelmingly felt …


Heavy Vehicle Rollover Propensity At Roundabouts On Highspeed Roads, Thomas M. Hall Oct 2014

Heavy Vehicle Rollover Propensity At Roundabouts On Highspeed Roads, Thomas M. Hall

Open Access Theses

There is a recent trend of building roundabouts on high-speed roads, often with significant heavy vehicle traffic. With the increased presence of trucks on roundabouts, the issue of rollover has become a concern. Geometric features that allow excessive speed on the approach and entry have been connected to rollover, as well as sudden changes in crossfall and radius. However, the effect on the rollover threshold of changing the roundabout's circulatory superelevation is not fully understood. The impact of aggressive driving behaviors, as displayed by high driver speed far from the roundabout, as well as errors that are manifested by the …


Capacity-Related Driver Behavior On Modern Roundabouts Built On High-Speed Roads, Shaikh Ahmad Oct 2014

Capacity-Related Driver Behavior On Modern Roundabouts Built On High-Speed Roads, Shaikh Ahmad

Open Access Theses

The objective of this thesis was to investigate the factors that affect capacity-related driver behavior on modern roundabouts built on high-speed roads. The capacity of roundabouts is strongly affected by the behavior of drivers as represented by critical headway (critical gap) and follow-up headway (follow-up time). The effects of heavy vehicles (single-unit truck, bus, and semi-trailer) and area type (rural or urban) on roundabout capacity were investigated by comparing the critical headways for roundabouts located on high-speed and low-speed roads. The effects of nighttime conditions (in the presence of street lighting) were also considered. Data were collected using the Purdue …


A Dynamic Stochastic Model For Converging Inbound Air Traffic, Jun Chen Oct 2014

A Dynamic Stochastic Model For Converging Inbound Air Traffic, Jun Chen

Open Access Theses

Weather accounts for the majority of congestion in the National Airspace System which highlights the importance of addressing weather uncertainty to mitigate delays, and this paper presents an effort in this direction. Firstly, a new dynamic stochastic 0-1 Integer Programming (IP) model is proposed, which models the Single Airport Ground Holding Problem (SAGHP) with respect to uncertainty in the separation between flights instead of Airport Acceptance Rate (AAR) or landing capacity. Uncertainty in separation according to different weather conditions is represented through the scenario tree by using stochastic linear programming. Considering time separation constraints instead of AAR constraints, our model …


Evaluation Of Lane Use Management Strategies, Chaitanya Paleti Siva Sai Krishna Oct 2014

Evaluation Of Lane Use Management Strategies, Chaitanya Paleti Siva Sai Krishna

Open Access Theses

The limited funding available for roadway capacity expansion and the growing funding gap, in conjunction with the increasing congestion, creates a critical need for innovative lane use management options. Various cost-effective lane use management strategies have been implemented in the United States and worldwide to address these challenges. However, these strategies have their own costs, operational characteristics, and additional requirements for field deployment. Hence, there is a need for systematic methodologies to evaluate lane use management strategies.

In this thesis, a systematic simulation-based methodology is proposed to evaluate lane use management strategies. It involves identifying traffic corridors that are suitable …


Research On Ship's Routeing And Reporting System Of The Malacca And Singapore, Xianwei Zhang Aug 2014

Research On Ship's Routeing And Reporting System Of The Malacca And Singapore, Xianwei Zhang

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.


Study On Safety Issues For Lng Tank Container Carried By Sea In China, Yuanjing Xiang Aug 2014

Study On Safety Issues For Lng Tank Container Carried By Sea In China, Yuanjing Xiang

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.


Research On The Maritime Safety In Qiongzhou Strait, Jiaxuan Li Aug 2014

Research On The Maritime Safety In Qiongzhou Strait, Jiaxuan Li

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.