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Full-Text Articles in Engineering

Carbon Sequestration By Reforesting Legacy Grasslands On Coal Mining Sites, James F. Fox, J. Elliott Campbell, Peter M. Acton Dec 2020

Carbon Sequestration By Reforesting Legacy Grasslands On Coal Mining Sites, James F. Fox, J. Elliott Campbell, Peter M. Acton

Civil Engineering Faculty Publications

Future carbon management during energy production will rely on carbon capture and sequestration technology and carbon sequestration methods for offsetting non-capturable losses. The present study quantifies carbon sequestration via reforestation using measurements and modeling for recent and legacy surface coal mining grasslands that are re-restored through tree planting. This paper focuses on a case study of legacy coal mining sites in the southern Appalachia the United States. This five million-hectare region has a surface mining footprint of approximately 12% of the land area, and the reclamation method was primarily grassland. The results of the soil carbon sequestration rates for restored …


Atmospheric Measurements With Unmanned Aerial Systems (Uas), Marcelo I. Guzman Nov 2020

Atmospheric Measurements With Unmanned Aerial Systems (Uas), Marcelo I. Guzman

Chemistry Faculty Publications

This Special Issue provides the first literature collection focused on the development and implementation of unmanned aircraft systems (UAS) and their integration with sensors for atmospheric measurements on Earth. The research covered in the Special Issue combines chemical, physical, and meteorological measurements performed in field campaigns as well as conceptual and laboratory work. Useful examples for the development of platforms and autonomous systems for environmental studies are provided, which demonstrate how careful the operation of sensors aboard UAS must be to gather information for remote sensing in the atmosphere. The work serves as a key collection of articles to introduce …


Kentucky Traffic Collision Facts 2019, Eric R. Green, Paul A. Ross, Christopher L. Blackden, Michael A. Fields, Kenneth R. Agent Oct 2020

Kentucky Traffic Collision Facts 2019, Eric R. Green, Paul A. Ross, Christopher L. Blackden, Michael A. Fields, Kenneth R. Agent

Kentucky Transportation Center Research Report

KENTUCKY’S TRAFFIC COLLISION FACTS report is based on collision reports submitted to the Kentucky State Police Records Branch. As required by Kentucky Revised Statutes 189.635:

“Every law enforcement agency whose officers investigate a vehicle accident of which a report must be made...shall file a report of the accident...within ten days after investigation of the accident upon forms supplied by the bureau.”

The stated purpose of this requirement is to utilize data on traffic collisions for such purposes as will improve the traffic safety program in the Commonwealth.


Analysis Of Traffic Crash Data In Kentucky 2015-2019, Eric R. Green, Paul A. Ross, Christopher L. Blackden, Michael A. Fields, William Nicholas Staats Oct 2020

Analysis Of Traffic Crash Data In Kentucky 2015-2019, Eric R. Green, Paul A. Ross, Christopher L. Blackden, Michael A. Fields, William Nicholas Staats

Kentucky Transportation Center Research Report

Executive Summary and Introduction

This report documents an analysis of traffic crash data in Kentucky. A primary objective of this study was to determine average crash statistics for Kentucky highways. Where used, rates were calculated for various types of highways and for counties and cities. Difference criteria were used for exposure.

Average and critical numbers, SPFs, and rates of crashes were calculated for various types of highways in rural and urban areas. These use crashes identified on highways where Annual Average Daily Traffic (AADT) volumes were available. The data in this report may be used to help identify problem areas. …


Cdl Data Quality Assessment, Valerie Keathley-Helil, Mallory Brown, Andrew Martin, Amir E. Najarzadeh, Brian K. Howell, Jennifer R. Walton Oct 2020

Cdl Data Quality Assessment, Valerie Keathley-Helil, Mallory Brown, Andrew Martin, Amir E. Najarzadeh, Brian K. Howell, Jennifer R. Walton

Kentucky Transportation Center Research Report

Quality issues related to commercial driver license (CDL) data present ongoing challenges to state and federal transportation agencies. This study highlights several problems with CDL data, including a lack of standardization for state-specific traffic infractions; process and workflow difficulties that degrade the accuracy, validity, and timeliness of data; adjudication procedures that can potentially mask serious violations from CDL driver history records; inadequate recordkeeping in state law enforcement citation and court case management software applications; outdated mainframe systems in urgent need of upgrades; IT personnel who are not paid enough; and insufficient reporting requirements for federal agencies that issue traffic citations. …


Determination Of Steels In Kentucky Bridges, Theodore Hopwood Ii, Christopher Goff, Sudhir Palle Oct 2020

Determination Of Steels In Kentucky Bridges, Theodore Hopwood Ii, Christopher Goff, Sudhir Palle

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet (KYTC) maintains over two hundred steel bridges constructed with types of steel which are unknown. Kentucky Transportation Center (KTC) researchers have developed a procedure for determining steel tensile properties (0.2% yield strength and ultimate tensile strength) which can be used to help identify unknown steels. The procedure involves extracting small coupons from the lower flanges of steel deck girder bridges. Coupons are then machined into sub-sized tensile testing specimens and suitable shapes for chemical analyses. Sub-sized tensile tests returned values generally comparable to those provided in mill certifications of steels purchased for laboratory trials. Several analytical …


Longer Service Life Bridge Coatings, Danny Wells, Theodore Hopwood, Bobby Meade, Sudhir Palle Sep 2020

Longer Service Life Bridge Coatings, Danny Wells, Theodore Hopwood, Bobby Meade, Sudhir Palle

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet (KYTC) has maintenance oversight responsibilities for approximately 1,100 steel bridges; it also helps local governments and other entities with maintenance painting on other steel bridges. Because maintaining steel bridges is costly, Cabinet officials asked Kentucky Transportation Center (KTC) researchers to identify materials and methods that will prolong their service lives. Steel bridges are uniquely vulnerable to deterioration resulting from exposure to atmospheric conditions (e.g. moisture, ultraviolet rays) and chlorides, the latter due to the application of deicing materials. This study examines two strategies for extending service lives. First, it appraises a novel method of hot dip …


Crash Data Analysis Tool: Research Report + User Guide, Eric R. Green, Paul Ross Sep 2020

Crash Data Analysis Tool: Research Report + User Guide, Eric R. Green, Paul Ross

Kentucky Transportation Center Research Report

This manual describes the Crash Data Analysis Tool (CDAT), which can be used by KYTC staff and the agency’s work partners to securely access crash datasets. CDAT users can query and download data using flags stored during post-processing. Unlike KyOPS, however, CDAT’s location data are validated using geographic coordinates and several of county, route, and milepoint fields to ensure crashes are properly geocoded. CDAT grants access to data and information that can be used in conjunction with KYTC’s Data Driven Safety Analysis (DDSA) Implementation Guide to conduct highway safety analysis numerous KYTC processes. Historically, the Cabinet’s Division of Traffic Operations …


Lessons Learned From Six Different Structural Health Monitoring Systems On Highway Bridges, Abheetha Peiris, Charlie Sun, Issam E. Harik Sep 2020

Lessons Learned From Six Different Structural Health Monitoring Systems On Highway Bridges, Abheetha Peiris, Charlie Sun, Issam E. Harik

Kentucky Transportation Center Faculty and Researcher Publications

Structural health monitoring has been utilized in numerous ways to investigate the performance and integrity of highway bridges. This paper highlights the use of six structural health monitoring systems, which were deployed to monitor distinct behaviors on six bridges in Kentucky. The structural health monitoring systems are as follows: (1) Over-height truck impact detection and monitoring on the I-64 over US 60 bridge, (2) Barge impact detection and monitoring on northbound US 41 over the Ohio River, (3) effectiveness of carbon fiber-reinforced polymer retrofit evaluation based on prestressed concrete I-girder crack movement on the I-65 elevated expressway in Louisville, (4) …


Scaling Realistic Fire Scenarios, James G. Quintiere Aug 2020

Scaling Realistic Fire Scenarios, James G. Quintiere

Progress in Scale Modeling, an International Journal

A review is made of work on scale modeling in fire and presented from the experience of the author. Primarily, scale modeling in air is discussed but there is a brief discussion of a scale model with salt and fresh water for smoke movement. A complete set of dimensionless groups is presented for fire, then it is illustrated how selections were made for the partial scaling of specific fire scenarios. Studies have been motivated by basic research interests as well as for fire investigations. The dynamics of floorcovering fire spread in a corridor is studied to reveal many features of …


Kentucky Transportation Cabinet Right Of Way Process Review (Phase I), Christopher W. Van Dyke, Bryan Gibson, Robin Baskette, Jeff Jasper, Candice Y. Wallace, Steven Douglas Kreis Aug 2020

Kentucky Transportation Cabinet Right Of Way Process Review (Phase I), Christopher W. Van Dyke, Bryan Gibson, Robin Baskette, Jeff Jasper, Candice Y. Wallace, Steven Douglas Kreis

Kentucky Transportation Center Research Report

From the Executive Summary:

The Kentucky Transportation Cabinet (KYTC) is responsible for planning, developing, constructing, and maintaining a prodigious inventory of roadway and bridge assets throughout the state. Project development is a complex process involving the coordination of numerous divisions and preconstruction disciplines across the Cabinet. On many projects, right-of-way (ROW) acquisition presents many challenges. Frequently, the ROW process is found on the critical path, meaning that it effectively governs a project’s overall duration. In some cases — especially on more complex projects — acquiring the ROW may take several years. Recognizing the need to shorten the duration and improve …


Recent Shrinkage And Fragmentation Of Bluegrass Landscape In Kentucky, Bo Tao, Yanjun Yang, Jia Yang, S. Ray Smith, James F. Fox, Alex C. Ruane, Jinze Liu, Wei Ren Jun 2020

Recent Shrinkage And Fragmentation Of Bluegrass Landscape In Kentucky, Bo Tao, Yanjun Yang, Jia Yang, S. Ray Smith, James F. Fox, Alex C. Ruane, Jinze Liu, Wei Ren

Plant and Soil Sciences Faculty Publications

The Bluegrass Region is an area in north-central Kentucky with unique natural and cultural significance, which possesses some of the most fertile soils in the world. Over recent decades, land use and land cover changes have threatened the protection of the unique natural, scenic, and historic resources in this region. In this study, we applied a fragmentation model and a set of landscape metrics together with the satellite-derived USDA Cropland Data Layer to examine the shrinkage and fragmentation of grassland in the Bluegrass Region, Kentucky during 2008–2018. Our results showed that recent land use change across the Bluegrass Region is …


Evaluation Of Alternative Rumble Strip Designs, William Nicholas Staats, Kenneth R. Agent, Brian K. Howell Jun 2020

Evaluation Of Alternative Rumble Strip Designs, William Nicholas Staats, Kenneth R. Agent, Brian K. Howell

Kentucky Transportation Center Research Report

Since Kentucky’s initial rumble strip designs were adopted, there has been additional research and experimentation in other states with alternative designs as a response to complaints from the public about noise pollution caused by rumble strips. The new research indicates that other rumble strip designs might provide increased interior noise/vibration with decreased exterior noise. Application of these alternative designs in Kentucky could result in improved rumble performance, reduced damage to new pavement, decreased noise pollution, installation on roadways with lower speed limits, and allow reinstallation of rumbles on thin overlays/microsurfacing.

The research team reviewed national and state guidelines for conventional …


Full-Depth Reclamation Of Asphaltic Concrete Pavements, Tony L. Beckham, Brad W. Rister, Charlie Sun Jun 2020

Full-Depth Reclamation Of Asphaltic Concrete Pavements, Tony L. Beckham, Brad W. Rister, Charlie Sun

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet (KYTC) has used a full-depth reclamation (FDR) process over the past few years to rehabilitate asphalt pavements exhibiting widespread base failures. FDR transforms existing hot-mix asphalt (HMA) pavement and underlying granular materials into a stabilized base layer. The stabilized layer is then overlaid with a new pavement surface layer. Until now, deciding when and how to use the FDR process has not been well specified in Kentucky — the Cabinet has commonly used a Special Note for Cement Stabilized Roadbed as guidance and relied on the contractor for acceptable materials design. Previous research conducted by the …


Crash Modification Factor Recommendation List, Reginald R. Souleyrette, Riana Tanzen, Eric R. Green, William Nicholas Staats, Federico Valentin Lause Iii Jun 2020

Crash Modification Factor Recommendation List, Reginald R. Souleyrette, Riana Tanzen, Eric R. Green, William Nicholas Staats, Federico Valentin Lause Iii

Kentucky Transportation Center Research Report

Practitioners use Crash Modification Factors/Functions (CMFs) to calculate the number of crashes expected once a countermeasure has been implemented. When evaluating design alternatives, CMFs can be used in conjunction with safety performance functions (SPFs) to derive crash predictions. The Federal Highway Administration (FHWA) maintains the CMF Clearinghouse as a repository for CMFs. Contributions are submitted by researchers across the U.S., Canada, and throughout the world. Typically, multiple CMFs are associated with a single countermeasure. Some CMFs only apply to specific facility or crash types. Furthermore, CMF quality varies, and some only apply to specific facility and/or crash types, regions, or …


Potential Effect Of Cable Median Barriers On Commercial Vehicle Crossover Crashes, Nikiforos Stamatiadis, Shraddha Sagar, Samantha Wright, Eric R. Green, Reginald R. Souleyrette, Michael A. Fields, Teng Alex Wang Jun 2020

Potential Effect Of Cable Median Barriers On Commercial Vehicle Crossover Crashes, Nikiforos Stamatiadis, Shraddha Sagar, Samantha Wright, Eric R. Green, Reginald R. Souleyrette, Michael A. Fields, Teng Alex Wang

Kentucky Transportation Center Research Report

In 2016, commercial motor vehicles (CMVs) were involved in 4,079 fatal crashes in the U.S., representing 11.8 percent of all fatal crashes. State of Kentucky crash data for 2015-2016 show that per capita crash rates and increases in crash-related fatalities exceeded the national average. Crossover crashes occur when a vehicle leaves its intended path and veers into the path of oncoming traffic, typically resulting in head-on or sideswipe opposite direction crashes. Cable median barriers are a countermeasure which can potentially be used to mitigate crossover crashes. This research investigated the potential effectiveness of cable median barriers on CMV crashes. Analysis …


Kytc Maintenance Field Operations Guide Supplement, Bryan Gibson, Candice Y. Wallace, Nancy Albright, Christopher W. Van Dyke, Steven Douglas Kreis Jun 2020

Kytc Maintenance Field Operations Guide Supplement, Bryan Gibson, Candice Y. Wallace, Nancy Albright, Christopher W. Van Dyke, Steven Douglas Kreis

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet (KYTC) is tasked with managing an asset portfolio that includes over 27,500 miles of roadway and 9,000 bridges. Keeping these assets in sound condition demands significant effort from KYTC’s Division of Maintenance, which includes activities ranging from mowing and litter pickup to cleaning out culverts and performing emergency roadway work. Despite the immense responsibilities shouldered by Maintenance personnel, until this project the Cabinet’s 12 districts lacked a systematic method for capturing and recording maintenance activities. Through a series of workshops held in each KYTC’s district with Section Engineer and Maintenance Supervisors, researchers at the Kentucky Transportation …


Traffic Incident Management Dashboard, Xu Zhang, Reginald R. Souleyrette, Alex Wang, Paul Ross, Eric R. Green, Mei Chen Jun 2020

Traffic Incident Management Dashboard, Xu Zhang, Reginald R. Souleyrette, Alex Wang, Paul Ross, Eric R. Green, Mei Chen

Kentucky Transportation Center Research Report

Traffic incidents remain all-too-common events on Kentucky’s roadways. They negatively impact the safety of the traveling public and emergency responders and cause significant traffic delays. Congestion associated with incidents can instigate secondary crashes, exacerbating safety risks and economic costs. Traffic incident management (TIM) provides an effective approach for managing highway incidents and reducing their occurrence and impacts. This report discusses the establishment of and methods of calculation for five TIM performance measures that can be used by the Kentucky Transportation Cabinet (KYTC) to improve incident response. The measures are: Roadway Clearance Time, Incident Clearance Time, Secondary Crashes, First Responder Vehicle …


Effect Of Socioeconomic Factors On Kentucky Truck Driver Crashes, Nikiforos Stamatiadis, Shraddha Sagar, Samantha Wright, Aaron Berry Cambron Jun 2020

Effect Of Socioeconomic Factors On Kentucky Truck Driver Crashes, Nikiforos Stamatiadis, Shraddha Sagar, Samantha Wright, Aaron Berry Cambron

Kentucky Transportation Center Research Report

Kentucky crash data for the 2015-2016 period reveal that per capita crash rates and increases in crash-related fatalities in the state outpaced the national average. To explain why the U.S. Southeast sees higher crash rates than other regions of the country, previous research has argued the region’s unique socioeconomic conditions provide a compelling explanation. Taking this observation as a starting point, this study uses an extensive crash dataset from Kentucky to examine the relationship between highway safety and socioeconomic and demographic characteristics. Its focus is single- and two-unit crashes that involve commercial motor vehicles (CMVs) and automobiles. Using binary logistic …


Structural Reinforcement, Reinforced Structural Member And Related Method, Issam E. Harik, Nisal Abheetha Peiris, Drew Christian Thompson, David Cambron Murray, Clayten Nicholas Greenwell May 2020

Structural Reinforcement, Reinforced Structural Member And Related Method, Issam E. Harik, Nisal Abheetha Peiris, Drew Christian Thompson, David Cambron Murray, Clayten Nicholas Greenwell

Civil Engineering Faculty Patents

A structural reinforcement includes a plurality of individual reinforcing elements. Each of the plurality of reinforcing elements includes a first end segment, a second end segment and an intermediate segment between the first and second end segments. A support engages the plurality of individual reinforcing elements along the intermediate segments and holds the elements in parallel.


Investigation Of Driver License Issuance Alternatives, Steven Andrew Martin, Abraham Najarzadeh, Jennifer R. Walton May 2020

Investigation Of Driver License Issuance Alternatives, Steven Andrew Martin, Abraham Najarzadeh, Jennifer R. Walton

Kentucky Transportation Center Research Report

This study develops an alternative model for issuing driver licenses and personal identifications in Kentucky. Under the current model, most licenses are distributed by circuit court clerks at 142 offices across the state while the Kentucky Transportation Cabinet (KYTC) provides central and regional support for specific license types. Given the cumbersome administrative structure and impending REAL ID requirements, both circuit clerks and KYTC administrators would like to explore an alternative distribution model. Researchers at the Kentucky Transportation Center (KTC) projected the costs of transitioning from the current issuance model to a centralized DMV model where licenses are distributed at 18 …


Construction-Ready Digital Terrain Models, Rachel Catchings, Steven Waddle, Hala Nassereddine, Gabriel B. Dadi, Makram Bou Hatoum, Walter Johnson May 2020

Construction-Ready Digital Terrain Models, Rachel Catchings, Steven Waddle, Hala Nassereddine, Gabriel B. Dadi, Makram Bou Hatoum, Walter Johnson

Kentucky Transportation Center Research Report

Since 2009, Kentucky has made its 3D design data available as a supplemental reference to bidders through the project delivery process. This research discusses methods for ensuring electronic engineering data (EED) — and specifically the proposed digital terrain model (DTM) — support modern construction management methods at the Kentucky Transportation Cabinet (KYTC). Researchers performed a literature review, surveyed KYTC construction and design staff, engaged with Cabinet staff and industry members to understand the current state of practice, and evaluated quality- related attributes of the EED through case studies. The report presents a set of targeted recommendations for improving KYTC processes …


Effect Of Socioeconomic Factors On Crash Occurrence, Nikiforos Stamatiadis, Shraddha Sagar, Samantha Wright, Aaron Berry Cambron May 2020

Effect Of Socioeconomic Factors On Crash Occurrence, Nikiforos Stamatiadis, Shraddha Sagar, Samantha Wright, Aaron Berry Cambron

Kentucky Transportation Center Research Report

Road traffic crashes are a leading cause of death in the United States. In Kentucky, per capita crash rates and crash-related fatalities have outpaced the national average for over a decade. Wanting to explain why the U.S. Southeast sees higher crash rates than other regions, researchers have argued the region’s unique socioeconomic conditions provide a compelling explanation. Taking this observation as a starting point, this study examined the relationship between highway safety and socioeconomic characteristics using an extensive crash dataset from Kentucky. This research sought to identify at-risk drivers based on the socioeconomic and demographic attributes of the zip codes …


Social Justice Mitigation In Transportation Projects: Why And How Lexington Fayette Urban County Government Can Support The Lexington Community Land Trust’S Path To Self-Sustainability, Pamela Clay-Young, Steven Douglas Kreis Apr 2020

Social Justice Mitigation In Transportation Projects: Why And How Lexington Fayette Urban County Government Can Support The Lexington Community Land Trust’S Path To Self-Sustainability, Pamela Clay-Young, Steven Douglas Kreis

Kentucky Transportation Center Research Report

The city of Lexington has reached a critical shortage of affordable housing available to families earning 80% - 50% of area median income (AMI). This study focuses on how to grow the Lexington CLT into self-sustainability while also narrowing the affordable housing gaps in Fayette County. Current research offers support for the city’s affordable housing program to adopt the community land trust model (CLT). The research recommends using tools such as the Lexington CLT, the Lexington-Fayette Urban County Landbank Authority (LFUCLA), and Lexington’s Affordable Housing Trust Fund, along with new development incentives, to develop a housing strategy that is cost …


Developing A Baseline For Customer Satisfaction In The Kentucky Transportation Cabinet's Department Of Vehicle Regulation, Steven Andrew Martin, Christopher W. Van Dyke, Jennifer R. Walton, Jeeyen Koo, Valerie Keathley Helil, Brian K. Howell Mar 2020

Developing A Baseline For Customer Satisfaction In The Kentucky Transportation Cabinet's Department Of Vehicle Regulation, Steven Andrew Martin, Christopher W. Van Dyke, Jennifer R. Walton, Jeeyen Koo, Valerie Keathley Helil, Brian K. Howell

Kentucky Transportation Center Research Report

Among the Kentucky Transportation Cabinet’s (KYTC) business units, the Department of Vehicle Regulation (DVR) has the most interactions with members of the public and other government agencies. Given its high profile and public visibility, it is critical for the department to provide high-quality customer service. Lacking data on customer perceptions of DVR’s level of service, the department commissioned researchers at the Kentucky Transportation Center (KTC) to conduct a baseline and rebaseline customer satisfaction surveys. Along with administering surveys to external customers, KTC’s research team also polled DVR staff to gauge employee morale and identify areas which could be improved. Approximately …


Analysis And Assessment Of The Reimbursement Rates And Mechanisms For Kentucky’S Publicly Funded Ferries, P. Gayle Marks, Bryan Gibson, Andrew Martin, Steven Douglas Kreis Feb 2020

Analysis And Assessment Of The Reimbursement Rates And Mechanisms For Kentucky’S Publicly Funded Ferries, P. Gayle Marks, Bryan Gibson, Andrew Martin, Steven Douglas Kreis

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet (KYTC) reimburses publicly operated ferries, including when they cease operations due to severe weather or unforeseen events. Reimbursement procedures are not codified in law and are largely based on historical practice. To determine how the Cabinet should handle reimbursement, funding, oversight of ferry services moving forward, the Kentucky Transportation Center (KTC) reviewed practices adopted by 10 other states and conducted a detailed analysis of Kentucky’s current approach. Of the states KTC examined, only Tennessee reimburses ferry operations for closures (at 50 percent of the normal hourly rate for a period up to 48 hours). Half of …


Estimating Free-Flow Speed With Lidar And Overhead Imagery, Armin Hadzic Jan 2020

Estimating Free-Flow Speed With Lidar And Overhead Imagery, Armin Hadzic

Theses and Dissertations--Computer Science

Understanding free-flow speed is fundamental to transportation engineering in order to improve traffic flow, control, and planning. The free-flow speed of a road segment is the average speed of automobiles unaffected by traffic congestion or delay. Collecting speed data across a state is both expensive and time consuming. Some approaches have been presented to estimate speed using geometric road features for certain types of roads in limited environments. However, estimating speed at state scale for varying landscapes, environments, and road qualities has been relegated to manual engineering and expensive sensor networks. This thesis proposes an automated approach for estimating free-flow …


Fluvial Sediment Organic Matter Degradation Identified With Elemental And Isotopic Fate During Laboratory Incubation, Brenden Riddle Jan 2020

Fluvial Sediment Organic Matter Degradation Identified With Elemental And Isotopic Fate During Laboratory Incubation, Brenden Riddle

Theses and Dissertations--Civil Engineering

Fluvial sediment is well recognized as a critical factor in both carbon and nutrient budgets within stream systems. However, we find very few studies of reactivity and isotope enrichment for stream water from agricultural and urban streams and the class of substrate known as fluvial sediment organic matter. This study investigated the hypothesis that fluvial sediment is subject to degradation even though many previous studies have considered this class of substrate generally inert. Therefore we qualify that elemental and isotopic signatures of fluvial sediment organic matter should be considered potentially non-conservative when used in tracer studies. Methods applied to this …


Effect Of Socioeconomic And Demographic Factors Of Driver Residence On Crash Occurrence, Shraddha Sagar Jan 2020

Effect Of Socioeconomic And Demographic Factors Of Driver Residence On Crash Occurrence, Shraddha Sagar

Theses and Dissertations--Civil Engineering

In the U.S., road traffic crashes are a leading cause of death. Crash data from the state of Kentucky shows that the per capita crash rates and crash-related fatalities were higher than the national average for over a decade. In effort to explain why the U.S. Southeast experiences higher crash rates than other regions of the country, previous research has argued the region’s unique socioeconomic provide a compelling explanation. Taking this observation as a starting point, this study examines the relationship between highway safety and socioeconomic characteristics using an extensive crash dataset from Kentucky.

The primary goal of this research …


The Relationship Between Roadway Homogeneity And Network Coverage For Network Screening, Riana Tanzen Jan 2020

The Relationship Between Roadway Homogeneity And Network Coverage For Network Screening, Riana Tanzen

Theses and Dissertations--Civil Engineering

In the context of transportation safety engineering, network screening is a method of identifying and prioritizing high-risk locations for potential safety investment. Since its release, the Highway Safety Manual (HSM) has facilitated the adoption of Safety Performance Functions (SPF) to predict the number of crashes for the network screening of any facility type. The predictive model becomes more reliable when developed from crash data with homogeneous roadway segments and this homogeneity can be attained by applying specific geometric attributes to the dataset. The caveat to this method is the requirement of adjustment factors (AFs) to adjust the predicted estimate for …