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Articles 511 - 540 of 850

Full-Text Articles in Civil and Environmental Engineering

Impacts Of Replacing A Tight Diamond Interchange With A Spui – A Wilsonville Interchange Study, Sina Vadaei Mar 2015

Impacts Of Replacing A Tight Diamond Interchange With A Spui – A Wilsonville Interchange Study, Sina Vadaei

Civil and Environmental Engineering Master's Project Reports

Tight diamond interchanges (TDI) and single point urban interchanges (SPUIs) are generally types of interchanges that can be used interchangeably in areas where right-of-way is constrained. There are limited amount of research conducted regarding the operational analysis and comparison of these two interchanges. The research that has been done regarding this topic are outdated and generally conclude that SPUIs perform better or about the same. Without knowing the true performances of the two interchange designs, it would make it difficult for engineers and planners to choose between the two interchanges.

This research study will use the current updated version of …


Multimodal Internal Waves Generated Over A Subcritical Ridge: Impact Of The Upper-Ocean Stratification, Xie Jieshuo, Jiayi Pan, David A. Jay Mar 2015

Multimodal Internal Waves Generated Over A Subcritical Ridge: Impact Of The Upper-Ocean Stratification, Xie Jieshuo, Jiayi Pan, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Interaction of barotropic tides with subsurface topography is vital to ocean mixing. Yet the behavior of large-amplitude, nonlinear, internal solitary waves (ISWs) that can cause strong mixing remains poorly understood, especially that of higher-mode and multimodal internal waves. Therefore, a 2.5-dimensional, nonhydrostatic model with adjustable vertical resolution was developed to investigate effects of upper-ocean stratification on tidally induced multimodal internal waves and to show how they are generated by the subcritical ridge where only upward-propagating internal wave beams (IWBs) are present. The effects of the stratification on properties and characteristics of the excited IWBs and on the energy partition of …


Identification And Quantification Of Gaseous Organic Compounds Emitted From Biomass Burning Using Two-Dimensional Gas Chromatography–Time-Of-Flight Mass Spectrometry, Lindsay E. Hatch, Wentai Luo, James F. Pankow, Robert J. Yokelson, Chelsea E. Stockwell, Kelley Barsanti Feb 2015

Identification And Quantification Of Gaseous Organic Compounds Emitted From Biomass Burning Using Two-Dimensional Gas Chromatography–Time-Of-Flight Mass Spectrometry, Lindsay E. Hatch, Wentai Luo, James F. Pankow, Robert J. Yokelson, Chelsea E. Stockwell, Kelley Barsanti

Civil and Environmental Engineering Faculty Publications and Presentations

The current understanding of secondary organic aerosol (SOA) formation within biomass burning (BB) plumes is limited by the incomplete identification and quantification of the non-methane organic compounds (NMOCs) emitted from such fires. Gaseous organic compounds were collected on sorbent cartridges during laboratory burns as part of the fourth Fire Lab at Missoula Experiment (FLAME- 4) and analyzed by two-dimensional gas chromatography– time-of-flight mass spectrometry (GC × GC–ToFMS). The sensitivity and resolving power of GC × GC–ToFMS allowed the acquisition of the most extensive data set of BB NMOCs to date, with measurements for 708 positively or tentatively identified compounds. Estimated …


On The Estimation Of Volumes Of Roadways: An Investigation Of Stop-Controlled Minor Legs, Joel Stephen Barnett Feb 2015

On The Estimation Of Volumes Of Roadways: An Investigation Of Stop-Controlled Minor Legs, Joel Stephen Barnett

Dissertations and Theses

This effort seeks to answer the question; can a transferable model be developed from easily obtainable, publicly available land-use, census, roadway, and network data for the use in safety performance functions? 474 stop-controlled minor legs were used as the training data set using ordinary least squares regression. A best-fit model of maximum independent variables, n=12 was chosen using an exhaustive approach using Mallow's Cp to select the model with least bias in the predictors. The results of the analysis revealed that the combination of variables from Washington, Ohio, and North Carolina did not have a strong relationship. The best-fit model …


Safety At Half-Signal Intersections In Portland, Oregon, Todd Robert Johnson Feb 2015

Safety At Half-Signal Intersections In Portland, Oregon, Todd Robert Johnson

Dissertations and Theses

The safety at half-signalized intersections in Portland, Oregon is analyzed in this thesis using 10 years of crash history and analysis of video that was collected at a subset of intersections. A half-signalized intersection has a standard red-yellow-green traffic signal for automobiles on the major road, a stop sign for motorists on the minor road, and a pedestrian signal with actuation for pedestrians and/or bicyclists on the minor road. Although prevalent in Canada, this type of intersection control is not typically found in the United States because the MUTCD explicitly prohibits its use. Half-signal use is limited mostly to two …


Modeling Regional Secondary Organic Aerosol Using The Master Chemical Mechanism, Jingyi Li, Meredith Cleveland, Luke D. Ziemba, Robert J. Griffin, Kelley Barsanti, James F. Pankow, Qi Ying Feb 2015

Modeling Regional Secondary Organic Aerosol Using The Master Chemical Mechanism, Jingyi Li, Meredith Cleveland, Luke D. Ziemba, Robert J. Griffin, Kelley Barsanti, James F. Pankow, Qi Ying

Civil and Environmental Engineering Faculty Publications and Presentations

A modified near-explicit Master Chemical Mechanism (MCM, version 3.2) with 5727 species and 16,930 reactions and an equilibrium partitioning module was incorporated into the Community Air Quality Model (CMAQ) to predict the regional concentrations of secondary organic aerosol (SOA) from volatile organic compounds (VOCs) in the eastern United States (US). In addition to the semi-volatile SOA from equilibrium partitioning, reactive surface uptake processes were used to simulate SOA formation due to isoprene epoxydiol, glyoxal and methylglyoxal. The CMAQ-MCM-SOA model was applied to simulate SOA formation during a two-week episode from August 28 to September 7, 2006. The southeastern US has …


Understanding Residential Location Choices For Climate Change And Transportation Decision Making: Phase 2 Report, Kelly J. Clifton, Steven R. Gehrke, Kristina Marie Currans Feb 2015

Understanding Residential Location Choices For Climate Change And Transportation Decision Making: Phase 2 Report, Kelly J. Clifton, Steven R. Gehrke, Kristina Marie Currans

Civil and Environmental Engineering Faculty Publications and Presentations

This research builds on the related Phase 1 project. In this second phase, we continue to study neighborhood and housing preferences that shape the residential location decision process. An online experimental survey tool is developed to investigate lifestyle preferences and tradeoffs that households make in their location decisions. This computer-aided experimental survey draws upon stated preference methods to engage participants in questions about residential location and transportation options. The survey infrastructure was extensively piloted (6-10% response rate). The 10-minute survey can be deployed for future investigations. This infrastructure is a contribution for the integration of visualized neighborhood typologies, or concepts, …


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 …


Analyzing Free-Base Nicotine Content In The Particulate Matter Of Mainstream Tobacco Smoke Using A Headpace Solid-Phase Microextraction Gc/Ms Method, Christopher S. Motti Jan 2015

Analyzing Free-Base Nicotine Content In The Particulate Matter Of Mainstream Tobacco Smoke Using A Headpace Solid-Phase Microextraction Gc/Ms Method, Christopher S. Motti

Civil and Environmental Engineering Master's Project Reports

The acid/base chemistry of cigarette smoke allows nicotine, the primary drug in mainstream tobacco smoke, to exist in protonated and free-base forms. Evidence suggests that most of the nicotine present in mainstream tobacco smoke is in the particle phase. αfb is the fraction of particle-phase nicotine in the free-base form. The magnitude and rate of nicotine deposition in the respiratory tract is dependent on αfb because only the free-base form of nicotine can volatilize from the particle phase of an inhaled aerosol and, once gaseous, rapidly deposit. This study develops a headspace solid-phase microextraction technique coupled with gas …


Geotechnical Statistical Evaluation Of Lahore Site Data And Deep Excavation Design, Aiza Malik Jan 2015

Geotechnical Statistical Evaluation Of Lahore Site Data And Deep Excavation Design, Aiza Malik

Civil and Environmental Engineering Master's Project Reports

Geotechnical characterization for foundation design is critical during preliminary planning, designing and feasibility studies of various engineering projects. In this research, an effort has been made to develop a geotechnical database for the city of Lahore, Pakistan. This database would aid geologists and engineers involved in the geotechnical design and planning of engineering projects in Lahore. The project area has been divided into zones geographically. Soil profiles have been developed for all zones, which provide ranges of soil properties and SPT-N values at regular intervals. Furthermore, the research also focuses on deep excavations in urban areas of Lahore, Pakistan and …


Parametric Study Of Rocking Shallow Foundations Under Seismic Excitation, Benjamin I. Herdrich Jan 2015

Parametric Study Of Rocking Shallow Foundations Under Seismic Excitation, Benjamin I. Herdrich

Civil and Environmental Engineering Master's Project Reports

Conventional design of structures relies on incorporating a certain level of inelastic deformation into select components to provide seismic energy dissipation, while ensuring the foundation remains relatively stationary. However, this inelasticity comes at the cost of severe damage to the structure, which often is no longer suitable to occupancy after a seismic event. In contrast with conventional structures, structures with rocking foundations shift the ductility demands away from the structure itself, and onto the underlying soil, which may result in less damage and greater stability. The purpose of this study is to explore the behavior and performance of a simple …


Key Aspects For Lrfd Implementation For Driven Pile Capacity By Dynamic Methods, Natalie R. Ehrlich Jan 2015

Key Aspects For Lrfd Implementation For Driven Pile Capacity By Dynamic Methods, Natalie R. Ehrlich

Civil and Environmental Engineering Master's Project Reports

Inputs and interpretation procedures for pile wave equation analysis, which correlates measured field dynamic driving response to axial pile static capacity, are highly dependent on site-specific soil conditions and field practices. The 6th Edition of the AASHTO LRFD Bridge Design Specifications provide generalized guidelines for pile design, but do not account for variability in region-specific soils and field practices. A comprehensive literature review of region-specific resistance factor recalibration efforts across the U.S. has given insight into the range of implementation issues encountered, especially the key decisions around choosing a restrike (BOR), along with measures of efficiency and treatment of …


A Microsimulation Of Novel Intersection Designs, Aman Kinfemichael Woldetinsae Jan 2015

A Microsimulation Of Novel Intersection Designs, Aman Kinfemichael Woldetinsae

Civil and Environmental Engineering Master's Project Reports

The focus of this project is to see how a turbo roundabout and a protected intersection designs behave when they are applied on two study sites in Portland, OR. PTV VISSM is used to model, analyze and compare the performances of these designs with the existing intersection. In addition, the best features of the protected intersection and the turbo roundabout were combined to create a new intersection design that is safer for the bicyclists and also performs better than the existing intersection.

The analysis is conducted for five different volume scenarios for both the study sites. The results of the …


Design Of Piles In Liquefied Soils For Combined Inertial And Kinematic Demands, Arash Khosravifar, J. Ugalde, T. Travasarou Jan 2015

Design Of Piles In Liquefied Soils For Combined Inertial And Kinematic Demands, Arash Khosravifar, J. Ugalde, T. Travasarou

Civil and Environmental Engineering Faculty Publications and Presentations

The design of piles penetrating liquefiable soils poses a number of challenges, including 1) accounting for the effects of liquefaction on lateral soil springs (p-y), 2) estimating liquefaction-induced kinematic demands (lateral spreading displacements) including pile-pinning effects, and 3) combining the effects of inertial demands from superstructure and kinematic demands from liquefied ground. This paper illustrates two approaches to address the above questions: A) a simplified decoupled approach adopting equivalent static analysis (ESA), and B) a detailed, coupled approach adopting nonlinear dynamic analyses (NDA). These approaches are presented through example projects showing the limitations and the potential conservatism associated with the …


Geostatistical Examination Of The Geotechnical Portland Bes Databases With Emphasis On Silt, Alex K. Baumann Jan 2015

Geostatistical Examination Of The Geotechnical Portland Bes Databases With Emphasis On Silt, Alex K. Baumann

Civil and Environmental Engineering Master's Project Reports

Willamette Valley silt deposits from historical catastrophic flood events present a difficult problem for subsurface engineers practicing in the Portland, Oregon area. Silts exhibit behavior of two very well-documented soil types, but publications containing mechanical properties for silts are scant, especially for local silts. Thus, the need for links between real Portland site investigation data and silt properties is high. To further exemplify the need for documented knowledge of local silts, this project reveals the evolving state of practice to incorporate more Pacific Northwest seismic analyses in preparation for a subduction zone earthquake. The geotechnical Portland BES databases contain thousands …


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, …


Dispersion Modeling Of Nitrogen Dioxide (No2) And Fine Particulate Matter (Pm2.5) From Backup Generators At Data Centers In Prineville, Oregon, Brooke E. Harmon Jan 2015

Dispersion Modeling Of Nitrogen Dioxide (No2) And Fine Particulate Matter (Pm2.5) From Backup Generators At Data Centers In Prineville, Oregon, Brooke E. Harmon

Civil and Environmental Engineering Master's Project Reports

As our society becomes increasingly dependent on digital communication (e.g., social media and email) and computerized storage (e.g., digitized medical records and government documents), tech giants such as Google, Facebook, and Apple are constructing and managing an increasing number of massive Internet data centers. These data centers house a network’s most critical systems and are vital to the continuity of daily operations. Requiring as much electricity as a medium size city, data centers rely on complex auxiliary power systems to prevent disruption to service. These backup systems consist of tens of multi-megawatt diesel-powered generators that release combustion byproducts, including over …


Pushover Analysis Of Retrofitted Reinforced Concrete Buildings, Hamidreza Nahavandi Jan 2015

Pushover Analysis Of Retrofitted Reinforced Concrete Buildings, Hamidreza Nahavandi

Civil and Environmental Engineering Master's Project Reports

For the past decade or more, the structural engineering profession has been using the nonlinear static procedure (NSP) or pushover analysis. Modeling for such analysis requires the determination of nonlinear properties of each component in the structure, quantified by strength and deformation capacities, which depend on the modeling assumptions. Pushover analysis is carried out for either user-defined nonlinear hinge properties or default-hinge properties, available in some programs based on the FEMA-356 such as SAP2000. While such documents provide the hinge properties for several ranges of detailing, programs may implement averaged values. In the realm of retrofitting of existing structures, few …


Dynamic Effect Of Light And Turbulence On Algal Photosynthetic Rate: A Water-Quality Model, Andres R. Rivas Jan 2015

Dynamic Effect Of Light And Turbulence On Algal Photosynthetic Rate: A Water-Quality Model, Andres R. Rivas

Civil and Environmental Engineering Master's Project Reports

Several studies provide evidence that algal photosynthetic rates depend on various changing factors such as light attenuation, temperature, and nutrient limitation (Chapra, 1997). However, recent papers show that turbulence and photosynthetic rate dynamics is also important (Ross, 2006). In this study, the photosynthetic rate model used is the one proposed by Chapra (1997), where it depends directly on temperature, nutrient and light limitation factors. At the same time, the effect of turbulence or random-walk of algae particles in the water column was also introduced in this model. To account for this factor, the model added was that proposed by Ross …


Safety At Intersections In Oregon: A Preliminary Update Of Statewide Intersection Crash Rates, Daniel R. Hazel Jan 2015

Safety At Intersections In Oregon: A Preliminary Update Of Statewide Intersection Crash Rates, Daniel R. Hazel

Civil and Environmental Engineering Master's Project Reports

This research aims to provide a preliminary update to statewide intersection crash rates for the state of Oregon using 2008-2013 crash data and a statewide sample of 129 intersections where two (or more) state-owned facilities intersect. Using intersections where state-owned facilities represent both the major and minor legs of the intersection allows for the maintenance of up-to-date intersection crash rates by eliminating time-intensive traffic volume data collection. Due to the frequency and severity of crashes at intersections, development of easily obtained intersection crash rates is important to assess trends and effectiveness of safety countermeasures employed at these locations in the …


The Skill Of Seasonal Ensemble Low-Flow Forecasts In The Moselle River For Three Different Hydrological Models, Mehmet C. Demirel, Martijn Booij, Arjen Hoekstra Jan 2015

The Skill Of Seasonal Ensemble Low-Flow Forecasts In The Moselle River For Three Different Hydrological Models, Mehmet C. Demirel, Martijn Booij, Arjen Hoekstra

Civil and Environmental Engineering Faculty Publications and Presentations

This paper investigates the skill of 90-day low-flow forecasts using two conceptual hydrological models and one data-driven model based on Artificial Neural Networks (ANNs) for the Moselle River. The three models, i.e. HBV, GR4J and ANN-Ensemble (ANN-E), all use forecasted meteorological inputs (precipitation P and potential evapotranspiration PET), whereby we employ ensemble seasonal meteorological forecasts. We compared low-flow forecasts for five different cases of seasonal meteorological forcing: (1) ensemble P and PET forecasts; (2) ensemble P forecasts and observed climate mean PET; (3) observed climate mean P and ensemble PET forecasts; (4) observed climate mean P and PET and (5) …


Modeling The Effects Of Congestion On Fuel Economy For Advanced Power Train Vehicles, Alexander Y. Bigazzi, Kelly J. Clifton Jan 2015

Modeling The Effects Of Congestion On Fuel Economy For Advanced Power Train Vehicles, Alexander Y. Bigazzi, Kelly J. Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

This paper describes research undertaken to establish plausible fuel-speed curves (FSC) for hypothetical advanced power train vehicles. These FSC are needed to account for the effects of congestion in long-term transportation scenario analysis considering fuel consumption and emissions. We use the PERE fuel consumption model with real-world driving schedules and a range of vehicle characteristics to estimate fuel economy (FE) in varying traffic conditions for light-duty internal combustion engine (ICE) vehicles, hybrid gas-electric vehicles (HEV), fully electric vehicles (EV), and fuel cell vehicles (FCV). FSC are fit to model results for each of 145 hypothetical vehicles. Analysis of the FSC …


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: …


Workshop Synthesis: Built Environment And Contextual Variables, Kelly Clifton, Pascal Perez Jan 2015

Workshop Synthesis: Built Environment And Contextual Variables, Kelly Clifton, Pascal Perez

Civil and Environmental Engineering Faculty Publications and Presentations

This two-day workshop focused on the important issue of how to define, convey and understand the built environment context as it relates to transport decisions. The field has grown tremendously over the last few decades, fueled in part by the increasing availability of archived spatial data about the environment and geo-referencing activity and travel patterns. But there are persistent issues particularly with inconsistencies in data format or availability across locations that hamper efforts to advance our understanding across regions. Further, there are new challenges in how we communicate context to survey respondents, particularly in stated preference surveys. Much of the …


Empirical Evaluation Of Transit Signal Priority Through Fusion Of Heterogeneous Transit And Traffic Signal Data And Novel Performance Measures, Wei Feng, Miguel A. Figliozzi, Robert Bertini Jan 2015

Empirical Evaluation Of Transit Signal Priority Through Fusion Of Heterogeneous Transit And Traffic Signal Data And Novel Performance Measures, Wei Feng, Miguel A. Figliozzi, Robert Bertini

Civil and Environmental Engineering Faculty Publications and Presentations

Transit signal priority (TSP) can reduce transit delay at signalized intersections by making phasing adjustments. TSP is a relatively inexpensive and easy to implement tool to make transit service faster and more reliable. TSP also sends a signal that a city or region encourages the growth of transit mode split. With the aim of assessing the performance of an existing TSP system, this study had access to a unique set of high-resolution bus and traffic signal data. Novel algorithms and performance measures to measure TSP performance are proposed. Results indicate that a timely and effective TSP system requires a high …


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 …


Roadway Determinants Of Bicyclist Multi-Pollutant Exposure Concentrations, Alexander Y. Bigazzi, Miguel A. Figliozzi Jan 2015

Roadway Determinants Of Bicyclist Multi-Pollutant Exposure Concentrations, Alexander Y. Bigazzi, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Due to poorly quantified traffic-exposure relationships, transportation professionals are unable to easily estimate exposure differences among bicycle routes for network planning, design, and analysis. This paper estimates the effects of roadway characteristics on bicyclist multi-pollutant exposure concentrations, controlling for meteorology and background conditions. Concentrations of volatile organic compounds (VOC), carbon monoxide (CO), and fine particulate matter (PM2.5) are modeled using high-resolution on-road data. This paper also compares exposure differences on immediately parallel high-traffic/low-traffic facilities and is the first study to quantify VOC exposure differences by facility. Results indicate that average daily traffic (ADT) provides a parsimonious way to characterize the …


Dynamic Ventilation And Power Output Of Urban Bicyclists, Alexander Y. Bigazzi, Miguel A. Figliozzi Jan 2015

Dynamic Ventilation And Power Output Of Urban Bicyclists, Alexander Y. Bigazzi, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Bicyclist intake of air pollutants is linked to physical exertion levels, ventilation rates, and exposure concentrations. Whereas exposure concentrations have been widely studied in transportation environments, there is relatively scant research linking on-road ventilation with travel conditions and exertion levels. This paper investigates relationships among power output, heart rate, and ventilation rate for urban bicyclists. Heart rate and ventilation rate were measured on-road and combined with power output estimates from a bicycle power model. Dynamic ventilation rates increased by 0.4-0.8% per watt of power output, with a mean lag of 0.8 minutes. The use of physiology (ventilation) monitoring straps and …


Empirical Analysis Of Bus Bunching Characteristics Based On Bus Avl/Apc Data, Wei Feng, Miguel A. Figliozzi Jan 2015

Empirical Analysis Of Bus Bunching Characteristics Based On Bus Avl/Apc Data, Wei Feng, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Bus bunching takes place when headways between buses are irregular. Bus bunching is associated with longer waiting times for riders, overcrowding in some buses, and an overall decrease on the level of service and capacity. Understanding the temporal and spatial characteristics and the causes and effects of bus bunching incidents from archived bus data can greatly aid transit agencies to develop efficient mitigation strategies. This paper presents methods to identify and visualize specific time periods and segments where bus bunching incidents occur based on automatic vehicle location (AVL) and automatic passenger count (APC) data. The paper also proposes methods that …


Does The Bicycle Detector Symbol Change Cyclist Queuing Position At Signalized Intersections?, Stefan W. Bussey, Christopher M. Monsere, Peter Koonce Jan 2015

Does The Bicycle Detector Symbol Change Cyclist Queuing Position At Signalized Intersections?, Stefan W. Bussey, Christopher M. Monsere, Peter Koonce

Civil and Environmental Engineering Faculty Publications and Presentations

The Manual of Traffic Control Devices (MUTCD) includes a bicycle detector pavement marking (Section 9C-05) and accompanying explanatory sign (R10-22) which may encourage cyclists to position themselves over detection at traffic signals. This paper presents the results of an observational and survey- based study evaluating the bicycle detector marking. Three minor actuated approaches at signalized intersections with significant bicycle volumes and without bicycle detector markings were selected for treatment. Three configurations were compared: 1) bicycle detector marking only 2) bicycle detector marking with the R10-22 explanatory sign, and 3) an alternative bicycle detector installed over a contrasting green rectangle. Analysis …