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

Engineering Commons™

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

Civil Engineering

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 9061 - 9090 of 11805

Full-Text Articles in Engineering

Feasibility Study Of Evaluating Durability Of Cfrp-Strengthened Beams Using In-Situ Load Test, Carlos Turizo-Rico Jan 2006

Feasibility Study Of Evaluating Durability Of Cfrp-Strengthened Beams Using In-Situ Load Test, Carlos Turizo-Rico

Electronic Theses and Dissertations

In Florida a number of highway bridges were retrofitted on their reinforced concrete (RC) girders with carbon-fiber reinforced polymers (CFRP) during the 1990's. Their conditions, after being in service for approximately 10 years, are of significant interest to the State's highway authority, as well as researchers in the region. This paper will evaluate if a load test on one of such bridges, which was retrofitted with CFRP at the girders in the splash-zone and thus was subjected to severe environmental conditions, is a feasible technique to evaluate the actual condition of the CFRP. A 3-dimensional Finite Element Model (FEM) was …


Improving Prediction Accuracy In Mechanistic-Empirical Pavement Design Guide, Scott Schram, Magdy Abdelrahman Jan 2006

Improving Prediction Accuracy In Mechanistic-Empirical Pavement Design Guide, Scott Schram, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Model calibration plays a fundamental role in the implementation of the mechanistic-empirical pavement design guide. The data used in the default calibration effort, which were afforded by the Long Term Pavement Performance (LTPP) database, have a network-level inference space. As implementation proceeds, state highway agencies may be inclined to calibrate at a local network level. However, with a focus on the calibration data set to local project-level conditions, model prediction error can be reduced further. Under this study, Nebraska Department of Roads Pavement Management System data were used to calibrate two design guide smoothness models at the local project level. …


Study Of Same-Lane And Inter-Lane Gvw Correlation, Bernard Enright, Eugene J. O'Brien, Colin C. Caprani Jan 2006

Study Of Same-Lane And Inter-Lane Gvw Correlation, Bernard Enright, Eugene J. O'Brien, Colin C. Caprani

Conference papers

The methodology used is to generate a number of years of simulated traffic and to use extreme value statistics to predict more accurately the characteristic loading for a given bridge. The parameters and probability distributions used in the Monte Carlo simulation must be based on observed sample traffic data. Some previous studies have made unsubstantiated assumptions regarding correlation between the Gross Vehicle Weights (GVW) of trucks in the same lane, or between trucks in adjacent, same-direction lanes. For this paper, an extensive database of Dutch Weigh-in-Motion data is analysed. Data are collected from two same-direction lanes and are time-stamped to …


Effectiveness Of Open-Graded Base Layer On Subgrade Moisture Regime And Overall Pavement Performance, Hassan Salem, Fouad Bayomy, Robert Smith, Magdy Abdelrahman Jan 2006

Effectiveness Of Open-Graded Base Layer On Subgrade Moisture Regime And Overall Pavement Performance, Hassan Salem, Fouad Bayomy, Robert Smith, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Rockcap (open-graded crushed aggregate with a nominal maximum size of 2.5 in.) base layer is commonly used in the construction of asphalt pavements in Idaho. The effectiveness of the rockcap layer on the subgrade moisture regime and the overall pavement performance were evaluated. Two pavement sites were selected in northern and southern regions of the state. At each site, two pavement sections that are identical and adjacent to each other were instrumented by temperature, frost, and moisture sensors using time domain reflectometry (TDR) probes. One was constructed by a well-graded 3/4-in. aggregate base, whereas the other was constructed by the …


Change Orders And Productivity Loss Quantification Using Verifiable Site Data, Engy Serag Jan 2006

Change Orders And Productivity Loss Quantification Using Verifiable Site Data, Engy Serag

Electronic Theses and Dissertations

Change orders occur frequently in most construction projects, where contract modifications that increase the contract value between 5 to 10% are expected. Changes occur not only because of errors and omissions, but also for other reasons such as scope of work changes, or changes because of unforeseen conditions encountered on the site; a problem which is very common in most heavy construction projects. Changes themselves might not cause productivity losses; in this case the damage calculation will be straightforward. However, changes may cause disruption in unchanged work where the working conditions are impacted, and as a result, lost productivity (inefficiency) …


Sensitivity Analysis Of Aashto's 2002 Flexible And Rigid Pavement Design Methods, Sanjay Shahji Jan 2006

Sensitivity Analysis Of Aashto's 2002 Flexible And Rigid Pavement Design Methods, Sanjay Shahji

Electronic Theses and Dissertations

Over the years pavement design has been based on empirical equations developed from the American Association of State Highway Transportation Officials (AASHTO) road tests. The various editions of the AASHTO pavement design guide have served well for several decades; nevertheless many serious limitations existed for their continued use as the nation's primary pavement design procedure. For example, the traffic loads and truck sizes have increased over the years, the AASHTO design equations were derived based on the climatic conditions present at the Road Tests site, and the issue of aging materials was not addressed in the design. To overcome these …


Transverse-Earthquake Induced Deformations Of A Bridge Approach Embankment In The New Madrid Seismic Zone, Wanxing Liu, Richard Wesley Stephenson, Ronaldo Luna Jan 2006

Transverse-Earthquake Induced Deformations Of A Bridge Approach Embankment In The New Madrid Seismic Zone, Wanxing Liu, Richard Wesley Stephenson, Ronaldo Luna

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

It is predicted that strong earthquakes, larger than M 7.0, may occur within next 50 years in the New Madrid Seismic Zone (NMSZ), the location of three of the most powerful earthquakes in United States history. Large displacements may occur during strong earthquakes that can cause an embankment to fail or lose its function. The hyperbolic stress-strain model with Masing rules was modified to account for strength and stiffness reduction due to change in the effective confining pressure. The Byrne model was combined with a hyperbolic model to calculate the pore water pressure caused by seismic shaking. This modified hyperbolic …


Systems Approach For Estimating Field Moisture Content, Thomas M. Petry, Yuh-Puu Han, David Newton Richardson Jan 2006

Systems Approach For Estimating Field Moisture Content, Thomas M. Petry, Yuh-Puu Han, David Newton Richardson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper describes a software tool developed for estimation of the field moisture content of subgrade materials. Subgrade behavior is directly related to its moisture content. Unfortunately, some approaches of estimating field moisture content are too complex to be used in routine design. In this paper, the authors attempt to provide an approach that is easy to use. The software presented here was developed using expert system approaches. It is capable of analyzing data entered by the users, and providing estimations to meet different scenarios. The information entered by the user is first examined for its reasonableness and accuracy. Then, …


Statistical Computation For Extreme Bridge Traffic Load Effects, Colin C. Caprani, E. J. O'Brien Jan 2006

Statistical Computation For Extreme Bridge Traffic Load Effects, Colin C. Caprani, E. J. O'Brien

Conference papers

The maintenance of highway infrastructure constitutes a major expenditure in many countries. This cost can be reduced significantly by minimizing the repair or replacement of highway bridges. In the assessment of existing bridges, the strength estimate tends to be more accurate than that of traffic loading, due to the more variable nature of loading. Recent advances in the statistical analysis of highway bridge traffic loading have resulted in more accurate forecasts of the actual loading to which a bridge is subject. While these advances require extensive numerical computation, they can significantly improve the accuracy of the calculation. This paper outlines …


Performance Evaluation Of The Permanent New Jersey Safety Shape Barrier – Update To Nchrp 350 Test No. 4-12 (2214nj-2), Karla A. Polivka, Ronald K. Faller, Dean L. Sicking, John R. Rohde, Robert W. Bielenberg, John D. Reid, Brian A. Coon Jan 2006

Performance Evaluation Of The Permanent New Jersey Safety Shape Barrier – Update To Nchrp 350 Test No. 4-12 (2214nj-2), Karla A. Polivka, Ronald K. Faller, Dean L. Sicking, John R. Rohde, Robert W. Bielenberg, John D. Reid, Brian A. Coon

Mid-America Transportation Center: Final Reports and Technical Briefs

Based on the proposed changes to the National Cooperative Highway Research Program (NCHRP) Report No. 350 guidelines, NCHRP Project 22-14(2) researchers deemed it appropriate to evaluate permanent safety shape barrier systems prior to finalizing the new crash testing procedures and guidelines. For this effort, the permanent New Jersey Safety Shape barrier was selected for evaluation. One full-scale vehicle crash test was performed on the longitudinal barrier system in accordance with the Test Level 4 (TL-4) requirements presented in the Update to NCHRP Report No. 350. For the permanent barrier testing program, a 10000S single unit truck was used.

The permanent …


Statistical Analysis Of Indiana Rainfall Data, A. Ramachandra Rao, Shih-Chieh Kao Jan 2006

Statistical Analysis Of Indiana Rainfall Data, A. Ramachandra Rao, Shih-Chieh Kao

JTRP Technical Reports

The basic objectives of research presented in this report are characterizing and modeling short time increment (hourly) rainfall data from Indiana. Characteristics of hourly rainfall data from Indiana were investigated. Data from 74 stations were used in the study.

The homogeneity of Indiana hourly rainfall data was tested as a part of the study. Indiana hourly rainfall data is found to be statistically homogeneous. Several probability distributions were evaluated. Surprisingly, both the type I extreme value as well as the generalized extreme value distributions were found to be acceptable to characterize Indiana hourly rainfall data. The generalized extreme value distribution …


Variation Of Geotechnical Strength Properties With Age Of Landfills Accepting Biosolids, Kishore Pinapati Jan 2006

Variation Of Geotechnical Strength Properties With Age Of Landfills Accepting Biosolids, Kishore Pinapati

Electronic Theses and Dissertations

The solid portion of waste disposal, known as Municipal Solid Waste (MSW) can be landfilled. Landfilling has proved to be a safe, sanitary and economical method of disposal. A by-product from wastewater treatment plants called biosolids is sometimes co-disposed along with MSW in landfills. Recent work at the University of Central Florida has focused on the behavior of the mixture of MSW and biosolids. As an increased amount of waste accumulates in these landfills, it creates a new problem – the geotechnical stability of landfills. In current literature, classical geotechnical testing methods have been followed to find the strength properties …


A Three-Dimensional Bay/Estuary Model To Simulate Water Quality Transport, Jing Yu Jan 2006

A Three-Dimensional Bay/Estuary Model To Simulate Water Quality Transport, Jing Yu

Electronic Theses and Dissertations

This thesis presents the development of a numerical water quality model using a general paradigm of reaction-based approaches. In a reaction-based approach, all conceptualized biogeochemical processes are transformed into a reaction network. Through the decomposition of species governing equations via Gauss-Jordan column reduction of the reaction network, (1) redundant fast reactions and irrelevant kinetic reactions are removed from the system, which alleviates the problem of unnecessary and erroneous formulation and parameterization of these reactions, and (2) fast reactions and slow reactions are decoupled, which enables robust numerical integrations. The system of species transport equations is transformed to reaction-extent transport equations, …


Driving Simulator Validation And Rear-End Crash Risk Analysis At A Signalised Intersection, Praveen Chilakapati Jan 2006

Driving Simulator Validation And Rear-End Crash Risk Analysis At A Signalised Intersection, Praveen Chilakapati

Electronic Theses and Dissertations

In recent years the use of advanced driving simulators has increased in the transportation engineering field especially in evaluating safety countermeasures. The driving simulator at UCF is a high fidelity simulator with six degrees of freedom. This research aims at validating the simulator in terms of speed and safety with the intention of using it as a test bed for high risk locations and to use it in developing traffic safety countermeasures. The Simulator replicates a real world signalized intersection (Alafaya trail (SR-434) and Colonial Drive (SR-50)). A total of sixty one subjects of age ranging from sixteen to sixty …


Developing Emergency Preparedness Plans For Orlando International Airport (Mco) Using Microscopic Simulator Watsim, Daniel Dawson Jan 2006

Developing Emergency Preparedness Plans For Orlando International Airport (Mco) Using Microscopic Simulator Watsim, Daniel Dawson

Electronic Theses and Dissertations

Emergency preparedness typically involves the preparation of detailed plans that can be implemented in response to a variety of possible emergencies or disruptions to the transportation system. One shortcoming of past response plans was that they were based on only rudimentary traffic analysis or in many cases none at all. With the advances in traffic simulation during the last decade, it is now possible to model many traffic problems, such as emergency management, signal control and testing of Intelligent Transportation System technologies. These problems are difficult to solve using the traditional tools, which are based on analytical methods. Therefore, emergency …


Analysis, Modeling, And Simulation Of The Tides In The Loxahatchee River Estuary (Southeastern Florida)., Peter Bacopoulos Jan 2006

Analysis, Modeling, And Simulation Of The Tides In The Loxahatchee River Estuary (Southeastern Florida)., Peter Bacopoulos

Electronic Theses and Dissertations

Recent cooperative efforts between the University of Central Florida, the Florida Department of Environmental Protection, and the South Florida Water Management District explore the development of a two-dimensional, depth-integrated tidal model for the Loxahatchee River estuary (Southeastern Florida). Employing a large-domain approach (i.e., the Western North Atlantic Tidal model domain), two-dimensional tidal flows within the Loxahatchee River estuary are reproduced to provide: 1) recommendations for the domain extent of an integrated, surface/groundwater, three-dimensional model; 2) nearshore, harmonically decomposed, tidal elevation boundary conditions. Tidal simulations are performed using a two-dimensional, depth-integrated, finite element-based code for coastal and ocean circulation, ADCIRC-2DDI. Multiple …


Utilizing A Real Life Data Warehouse To Develop Freeway Travel Time Eliability Stochastic Models, Emam Emam Jan 2006

Utilizing A Real Life Data Warehouse To Develop Freeway Travel Time Eliability Stochastic Models, Emam Emam

Electronic Theses and Dissertations

During the 20th century, transportation programs were focused on the development of the basic infrastructure for the transportation networks. In the 21st century, the focus has shifted to management and operations of these networks. Transportation network reliability measure plays an important role in judging the performance of the transportation system and in evaluating the impact of new Intelligent Transportation Systems (ITS) deployment. The measurement of transportation network travel time reliability is imperative for providing travelers with accurate route guidance information. It can be applied to generate the shortest path (or alternative paths) connecting the origins and destinations especially under conditions …


Coordination, Matchmaking, And Resource Allocation For Large-Scale Distributed Systems, Xin Bai Jan 2006

Coordination, Matchmaking, And Resource Allocation For Large-Scale Distributed Systems, Xin Bai

Electronic Theses and Dissertations

In this research, statistical models of airport delay and single flight arrival delay were developed. The models use the Airline On-Time Performance Data from the Federal Aviation Administration (FAA) and the Surface Airways Weather Data from the National Climatic Data Center (NCDC). Multivariate regression, ANOVA, neural networks and logistic regression were used to detect the pattern of airport delay, aircraft arrival delay and schedule performance. These models are then integrated in the form of a system for aircraft delay analysis and airport delay assessment. The assessment of an airport¡¯s schedule performance is discussed. The results of the research show that …


Hydrologic Mass Balance Of Pervious Concrete Pavement With Sandy Soils, Thomas Kunzen Jan 2006

Hydrologic Mass Balance Of Pervious Concrete Pavement With Sandy Soils, Thomas Kunzen

Electronic Theses and Dissertations

Use of pervious concrete pavement as a method of stormwater management has shown great promise in previous studies. Reduction in runoff, water quality improvements, and long-term economic benefits are but a few of its many advantages. Regulatory agencies such as the St. Johns River Water Management District require further research into the performance of pervious concrete pavement before granting credits for its use as a best management practice in controlling stormwater. As a part of a larger series of studies by UCF's Stormwater Management Academy, this thesis studies the hydrologic mass balance of pervious concrete pavement in sandy soil common …


Safety Analyses At Signalized Intersections Considering Spatial, Temporal And Site Correlation, Xuesong Wang Jan 2006

Safety Analyses At Signalized Intersections Considering Spatial, Temporal And Site Correlation, Xuesong Wang

Electronic Theses and Dissertations

Statistics show that signalized intersections are among the most dangerous locations of a roadway network. Different approaches including crash frequency and severity models have been used to establish the relationship between crash occurrence and intersection characteristics. In order to model crash occurrence at signalized intersections more efficiently and eventually to better identify the significant factors contributing to crashes, this dissertation investigated the temporal, spatial, and site correlations for total, rear-end, right-angle and left-turn crashes. Using the basic regression model for correlated crash data leads to invalid statistical inference, due to incorrect test statistics and standard errors based on the misspecified …


Development Of A Simplified Finite Element Approach For Frp Bridge Decks., Jignesh Vyas Jan 2006

Development Of A Simplified Finite Element Approach For Frp Bridge Decks., Jignesh Vyas

Electronic Theses and Dissertations

Moveable bridges in Florida typically use open steel grid decks due to the weight limitations. However, these decks present rideability, environmental, and maintenance problems, for they are typically less skid resistant than a solid riding surface, create loud noises, and allow debris to fall through the grids. Replacing open steel grid decks that are commonly used in moveable bridges with a low-profile FRP deck can improve rider safety and reduce maintenance costs, while satisfying the strict weight requirement for such bridges. The performance of the new deck system, which includes fatigue and failure tests were performed on full-size panels in …


Using Augmented Reality For Studying Left Turn Maneuver At Un-Signalized Intersection And Horizontal Visibility Blockage, Ghada Moussa Jan 2006

Using Augmented Reality For Studying Left Turn Maneuver At Un-Signalized Intersection And Horizontal Visibility Blockage, Ghada Moussa

Electronic Theses and Dissertations

Augmented reality "AR" is a promising paradigm that can provide users with real-time, high-quality visualization of a wide variety of information. In AR, virtual objects are added to the real-world view in a real time. Using the AR technology can offer a very realistic environment for driving enhancement as well as driving performance testing under different scenarios. This can be achieved by adding virtual objects (people, vehicles, hazards, and other objects) to the normal view while driving in a safe controlled environment. In this dissertation, the feasibility of adapting the AR technology into traffic engineering was investigated. Two AR systems; …


Simulation And Continuance Of Operation For The Use Of Transit (Lynx) To Be Used In Emergency Evacuation Incidents, Noor Elmitiny Jan 2006

Simulation And Continuance Of Operation For The Use Of Transit (Lynx) To Be Used In Emergency Evacuation Incidents, Noor Elmitiny

Electronic Theses and Dissertations

The evacuation planning has become an important issue addressed by many research studies and publications aiming to improve the security of the daily life for our public inside the United States of America. The main objective of this research was to address the growing need for evacuation planning using traffic simulation. With increased interests and awareness in emergency evacuation and first responder access to emergencies in public locations (airports, transit stations, ports or stadiums), the traffic simulation can be helpful in orchestrating the traffic flow during emergencies. Related to this issue, Federal Transit Administration has issued a large number of …


Effects Of Fiber And Lithium On Mechanical Properties Of Concrete Made Fromrecycled Concrete Aggregate, Ashraf Eskander Jan 2006

Effects Of Fiber And Lithium On Mechanical Properties Of Concrete Made Fromrecycled Concrete Aggregate, Ashraf Eskander

Electronic Theses and Dissertations

The growing demand of construction aggregates has raised concern about the availability of natural aggregates. Over two billion tons of natural aggregate are produced each year in the United States and that number is expected to increase to 2.5 billion tons by 2020. This has raised concern about the availability of natural aggregate. Discarding demolished concrete into landfills is a costly solution from an economical and environmental point of view. Many U.S. highway agencies are re-using Recycled Concrete Aggregates (RCA) as construction material. The use of fiber reinforcement in Portland Cement Concrete (PCC) has recently become a popular option in …


Safety Effects Of Traffic Signal Installations On State Road Intersections In Northeast Florida, Christopher Ledew Jan 2006

Safety Effects Of Traffic Signal Installations On State Road Intersections In Northeast Florida, Christopher Ledew

Electronic Theses and Dissertations

The purpose of this thesis is to explore how the installations of traffic signals affect crash experience at intersections, to identify those factors which help predict crashes after a signal is installed, and to develop a crash prediction model. It is the intent of this thesis to supplement the Manual on Uniform Traffic Control Devices Signal Warrant procedure and aid the traffic engineer in the signal installation decision making process. Crash data, as well as operational and geometric factors were examined for 32 state road intersections in the northeast Florida area before and after signal installation. Signal warrant studies were …


Coupling Of Hydrodynamic And Wave Models For Storm Tide Simulations: A Case Study For Hurricane Floyd (1999), Yuji Funakoshi Jan 2006

Coupling Of Hydrodynamic And Wave Models For Storm Tide Simulations: A Case Study For Hurricane Floyd (1999), Yuji Funakoshi

Electronic Theses and Dissertations

This dissertation presents the development of a two-dimensional St. Johns River model and the coupling of hydrodynamic and wave models for the simulation of storm tides. The hydrodynamic model employed for calculating tides and surges is ADCIRC-2DDI (ADvanced CIRCulation Model for Shelves, Coasts and Estuaries, Two-Dimensional Depth Integrated) developed by Luettich et al. (1992). The finite element based model solves the fully nonlinear shallow water equations in the generalized wave continuity form. Hydrodynamic applications are operated with the following forcings: 1) astronomical tides, 2) inflows from tributaries, 3) meteorological effects (winds and pressure), and 4) waves (wind-induced waves). The wave …


Developing Microscopic Toll Plaza Model Using Paramics, Nezamuddin Nezamuddin Jan 2006

Developing Microscopic Toll Plaza Model Using Paramics, Nezamuddin Nezamuddin

Electronic Theses and Dissertations

Simulation modeling is the most cost-effective way of studying real life transportation problems, either existing or anticipated, without disturbing the balance of the transportation system. There is a vast suite of simulation models available in market, ready to choose from macroscopic, mesoscopic, or microscopic in nature, to study different transportation system elements like freeways, highways, signalized and un-signalized intersections. However, most of these network simulation models, like PARAMICS, VISSIM, CORSIM … etc, do not come readily available with built in toll plaza models. On the other hand, many researchers have independently developed toll plaza models, which can only model an isolated …


Determination Of Ash Mixture Properties And Construction Of Test Embankment - Part B, Sungmin Yoon, Umashankar Balunaini, Monica Prezzi, Rodrigo Salgado, Nayyar Zia Siddiki Jan 2006

Determination Of Ash Mixture Properties And Construction Of Test Embankment - Part B, Sungmin Yoon, Umashankar Balunaini, Monica Prezzi, Rodrigo Salgado, Nayyar Zia Siddiki

JTRP Technical Reports

Class F fly ash and bottom ash are solid residue byproducts produced by coal-burning plants. They are usually disposed off with a typical disposal rate of 80 % fly ash and 20 % bottom ash. To maximize the use of the coal ash, and thus significantly reduce the disposal problem that electric utility companies and our society in general face, the direct use of ponded or landfilled ash that is composed of high proportions of fly ash would be desirable. However, a general understanding of the behavior of high volume fly ash mixtures is needed. Although there have been investigations …


Evaluation Of Stop Bar Video Detection Accuracy At Signalized Intersections, Avery Rhodes, Darcy M. Bullock, James R. Sturdevant, Zachary Thomas Clark Jan 2006

Evaluation Of Stop Bar Video Detection Accuracy At Signalized Intersections, Avery Rhodes, Darcy M. Bullock, James R. Sturdevant, Zachary Thomas Clark

JTRP Technical Reports

Many agencies nationwide have adopted video vehicle detection technology as an alternative to inductive loops. While many product evaluations have been performed, the majority of these evaluations have concentrated on freeway applications where speed and volume were the primary evaluation criteria. At an actuated intersection, the metrics of speed and volume do not necessarily represent how well a device will operate as a presence detector. Video detection was evaluated at two signalized intersections in West Lafayette, Indiana and Noblesville, Indiana. A camera on each approach was located at the vendor recommended position, at a height of 40 feet and offset …


Feasibility Study For Bicycle Safety: Data Assessment And Network Evaluation, Michael Seth Klobucar, Jon D. Fricker Jan 2006

Feasibility Study For Bicycle Safety: Data Assessment And Network Evaluation, Michael Seth Klobucar, Jon D. Fricker

JTRP Technical Reports

Bicycles offer a promising transportation alternative to private motor vehicles, especially in areas with congestion, poor air quality, and high fuel prices. This study sought rational methods for evaluating the benefits of incorporating bicycle-friendly features into highway project designs. Data on recent bicyclist fatalities and other collisions involving bicyclists in Indiana were analyzed to determine factors that could help to explain the incidents and offer insights into countermeasures or remedies. Human error – on the part of the bicyclist or the motorist – was found to be the most common factor. Poor lighting and noncompliance with sidewalk ordinances also were …