Civil and Environmental Engineering Commons^™

Congestion And Travel Time Reliability Performance Measures For Shift 2026, Mei Chen, Eugene Antwi, Xu Zhang

Kentucky Transportation Center Research Report

Researchers obtained and processed probe speed data from HERE Technologies and integrated them with the Kentucky Transportation Cabinet’s highway inventory to develop congestion and travel time reliability performance metrics. This report summarizes analyses conducted using HERE speed data for 2022 – 2023. HERE data were processed using an established methodology, after which they were aligned with Kentucky’s highway inventory network. Analysis found that 2022 – 2023 HERE data offer significant improvements in coverage and quality over previous years. For locations that lacked sufficient data, researchers used HERE’s speed model to estimate hourly speeds. Data were used to calculate congestion and …

Balancing Infrastructure Demands: Analysis Of Materials Pricing And Supply, Bethany Paris, Ying Li, Steve Waddle, Bryan Gibson

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet (KYTC) lets around 700 contracts year valued at over $1 billion. One of KYTC’s foremost goals is to deliver projects on time and on budget. However, over the past five years achieving these twin goals has grown in difficulty due to material shortages, widespread inflation, supply chain disruptions, and the tight labor market triggered by the COVID-19 pandemic. Although material shortages have abated and supply chain disruptions have eased, instability is seemingly a permanent feature of the national and global economies. As such, Cabinet decision makers need reliable tools that can be used to understand historical …

Enhanced Pavement Project Prioritization, Bryan Gibson, Jon Wilcoxson, Gayle Marks

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet (KYTC) is responsible for inspecting, maintaining, and improving 27,000 centerline miles of pavement. Given the vastness of the state’s transportation network, KYTC needs a robust method for prioritizing pavement preservation projects. The Cabinet has relied on pavement condition ratings, data collected using Laser Crack Measurement Systems, and input from district-level staff to prioritize these types of projects. But this approach overlooks information that should be considered, such as factors related to safety, mobility, and geographic context. To resolve these shortcomings, Kentucky Transportation Center (KTC) researchers worked with KYTC subject-matter experts to develop the Enhanced Pavement Prioritization …

Stabilizing Embankments Using Geosynthetic Reinforcement, Daryl Greer, Charlie Sun

Kentucky Transportation Center Research Report

Reinforced soil slopes (RSSs) can be a feasible solution for embankments where there exist right of way re-strictions, environmental issues, rolling or mountainous topography, unfavorable geology, and other limiting fac-tors. They can be an alternative to retaining walls or importing select fills to construct steeper, stable embankment slopes where flatter embankment slopes may result in unwanted impacts, costs, and maintenance issues. Thisreport discusses the advantages and limitations of using geosynthetic reinforcement to construct RSSs. Researchers investigated current design, specification, and construction practices to determine which practices can be adopted by the Kentucky Transportation Cabinet (KYTC). Specifications were developed for using …

Development Of A Health And Wellness Assessment For Kytc Personnel, Gabriel Dadi, Farshid Taherpour, Caitlin Pope

Kentucky Transportation Center Research Report

Highway construction workers operate in high-stress, hazardous settings where they have to perform physically taxing labor in environments where exposure to variable weather conditions, heavy equipment, high volumes of vehicle traffic, and other conditions that induce stress and anxiety are the norm. Up to 70% of workers in this industry have reported experiencing mental health issues, including secondary traumatic stress, post-traumatic stress disorder, depression, anxiety, and substance abuse disorders. Few state departments of transportation, however, offer adequate resources staff can draw on to effectively manage their psychological well-being. To help Kentucky Transportation Cabinet (KYTC) roadway maintenance and construction workers develop …

Research Into Job Classifications For Kentucky Department Of Vehicle Regulation Employees, Mallory Brown, Andrew Martin, Jeeyen Koo, Jennifer Walton

Kentucky Transportation Center Research Report

The Kentucky Department of Vehicle Regulation (DVR) faces persistent challenges with employee recruitment, retention, and workforce alignment due to outdated job classifications and compensation structures. This study investigates if DVR’s reliance on the general Administrative Specialist job series is warranted given the duties performed by its staff. Through a job task analysis, financial modeling, and personnel data review, researchers assessed the feasibility of introducing a new DVR-specific job series based on the Vehicle Regulation Specialist (VRS) position currently being used by the Division of Motor Carriers. The proposed VRS series includes two levels — VRS I (Grade 13) and VRS …

Development Of Measures For Highway Criticality Assessment, Xu Zhang, Mei Chen

Kentucky Transportation Center Research Report

Existing network criticality assessments, often biased towards heavily used highways in populous areas by incorporating traffic and sociodemographic attributes, can lead to an underestimation of the vital role of rural infrastructure. Consequently, rural highways, particularly low-volume roads, often receive less consideration despite their critical role in network connectivity and local access to services and economic opportunities. To address this, we develop a criticality framework based on the egalitarian principle, which prioritizes equitable consideration of all network links regardless of traffic volume or population density, comprising two complementary measures. First, the normalized betweenness centrality quantifies a road's relative importance in efficiently …

Current Practices In Rock Scaling, Daryl J. Greer, Kean H. Ashurst Jr

Kentucky Transportation Center Research Report

Rockfalls, which result from the chemical and physical weathering of aging exposed rock cuts, occur frequently along many Kentucky roadways and can endanger travelers. Mitigating rockfalls often requires substantial excavation, procuring additional right of way, and/or hiring specialty contractors. An alternative to these expensive processes is rock scaling, which can be a cost-effective tool for mitigating rockfalls. Rock scaling entails removing loose and unstable rocks from rock cut slopes within the right of way to reduce rockfall risk and is being used with increased frequency by state transportation agencies around the country. The Kentucky Transportation Cabinet (KYTC) has completed several …

Bridge Load Posting Based On Load Testing, Cody Hutchinson, Abheetha Peiris, Issam Harik

Kentucky Transportation Center Research Report

AASHTO’s Manual for Bridge Evaluation (MBE) provides guidance for analytically evaluating bridge capacity based on available design information and the results of field inspections. This analysis results in a rating factor (RF), which quantifies a bridge’s safe load carrying capacity. RF accuracy, however, depends on the availability of information about structural details and material properties. As such, load rating bridges without design plans is difficult as field inspections alone often cannot provide enough information to perform detailed analysis. In many instances this means that a bridge would possess a substandard rating factor (RF < 1.0) simply due to the conservative assumptions required to perform traditional analysis. The most effective method for safely modifying such conservative theoretical rating factors is through load testing. Load testing measures actual bridge behavior and, for most bridges in good health, finds an increase in load rating is justified. This project utilized load testing to load rate 14 bridges in Kentucky that lack structural plans. Researchers first determined theoretical ratings using MBE-prescribed methods. For information typically taken from design plans, but which could not be measured directly, data-backed methods for making conservative assumptions were developed. For most bridges included in the study, theoretical rating factors alone suggested load postings were necessary. Load testing was then carried out utilizing tandem rear-axle dump trucks with measured axle weights. Multiple single-lane load cases were selected to maximize the effects being rated. Strain data were collected in real time using a wireless reusable strain gage system. Using these data, researchers computed a field test adjustment factor using MBE methods which directly modified the calculated theoretical RFs. Ultimately, load testing provided sufficient evidence to safely recommend that load postings were not necessary for any bridges in this study.

A Framework For Ai Implementation In Construction: Use Cases, Challenges, And Benefits For Contractors, Jaqueline De Aquino Leite Gomes

Theses and Dissertations--Civil Engineering

The construction industry is one of the most important sectors that contribute to the economy worldwide, but it has been very slow in adopting digital transformation. Artificial Intelligence is the backbone of digital innovation, and it can help solve inefficiencies, improve safety, and enhance decision-making in construction. This thesis reviews 85 academic papers, identifies 354 AI use-cases, 180 benefits, and 173 challenges. Key findings have looked at the role of AI in safety monitoring, design optimization, and operational efficiency, while barriers involve data scarcity, high costs, and readiness of the workforce.

All of these challenges have one very handy framework …

Seasonal Variation Of The Stream’S Autogenic Sediment Transport Regime, Melissa Beckman

Theses and Dissertations--Civil Engineering

This thesis investigates the autogenic sediment transport regime in a low-gradient stream system in the inner bluegrass region of central Kentucky, USA The seasonality of sediment transport seasonality was not well addressed in prior research for baseflow and low flow periods, to our knowledge, due to the assumption that low flows do not account for considerable fluid transport capacity to move sediment. The hypothesis is that during the autogenic regime the sediment transport in the low-gradient system is being driven by geophysical, biogeochemical, and biological processes. We hypothesize that crayfish are one mechanical driver of sediment transport during these periods. …

Stable Oxygen And Hydrogen Isotopic Ratios Of Precipitation And Modelling Of Precipitation Sources In Central Kentucky, Usa, 2017-2022, Ariel Gold-Mccoy

Theses and Dissertations--Civil Engineering

Our goals were to carry out analyses of a multi-year δ¹⁸O and δ²H dataset of precipitation from central Kentucky and to analyze the source of precipitation for storm events from 2017 to 2022. δ¹⁸O and δ²H were measured for 244 weekly precipitation samples collected by the National Atmospheric Deposition Program at Mackville, Kentucky, USA. Modelling precipitation source was carried out using HYSPLIT model for 414 events. Results of δ¹⁸O and δ²H from central Kentucky show: consistent seasonality, including summer highs and winter lows for δ¹⁸O and δ²H; correlation with air temperature; and …

Measuring Accessibility Of Electric Vehicle Charging Infrastructure: A Case Study In Kentucky, Oluwasola Elijah Fagbohun

Theses and Dissertations--Civil Engineering

This thesis assesses spatial accessibility to electric vehicle charging infrastructure across Kentucky by investigating methodological approaches to measure accessibility: provider-topopulation ratios, regional accessibility metrics, and several methods in the family of gravity models. The Enhanced Two-Step Floating Catchment Area method was employed to measure electric vehicle charging station accessibility across Kentucky using a network-based approach in ArcGIS Pro. The analysis integrated 2023 American Community Survey 5-year Census block group data, Kentucky road network datasets, charging station locations from the Alternative Fuels Data Center, and Alternative Fuel Corridor designations. We examined existing infrastructure and proposed stations outlined in the Kentucky electric …

A Scoring Approach For Evaluating And Ranking Complete Streets Projects, Eirini Stavropoulou

Theses and Dissertations--Civil Engineering

Complete Streets is a vital strategy for developing an equitable transportation network that provides access to all users and transportation options to communities. A growing interest in this concept has been noted in the United States, with over 1,700 Complete Streets-related policies implemented nationwide. The Kentucky Transportation Cabinet (KYTC) has developed the “Complete Streets, Roads, and Highways Manual” and the “Complete Streets Policy” aiming to promote a safer and more inclusive transportation system statewide through Complete Streets implementation. A recent KYTC initiative was the development of a scorecard to systematically evaluate Complete Streets projects competing for funding. The scorecard is …

Adjusting Benefit Estimation For Pedestrian And Bicycle Facilities For Kentucky, Dionysios Tzamakos

Theses and Dissertations--Civil Engineering

The growing shift of commuters towards active transportation (AT) in the U.S. has led transportation agencies to place greater emphasis on improving bicycle and pedestrian facilities. Such improvement efforts can be integrated into multi-modal highway planning and development or be implemented through stand-alone pedestrian and bicycle projects both resulting in additional AT demand. Measuring the benefits of infrastructure improvement is central to prioritizing projects, as active transportation contributes to health, congestion reduction, safety, and recreational benefits. This study aims to calibrate the demand estimates for walking and cycling and estimate the associated benefits for the state of Kentucky. Population density …

Advancing Vapor Intrusion Science Using Systematic Frameworks To Foster Informed Decision Making, Hong Cheng Tay

Theses and Dissertations--Civil Engineering

Vapor intrusion, the migration of subsurface vapors into indoor air spaces, is an important source of indoor air contamination to consider at hazardous waste sites contaminated by volatile organic compounds (VOCs). There is considerable uncertainty and variability in the factors that influence vapor intrusion processes, which poses a significant challenge for decision making, despite advancements in vapor intrusion science. This dissertation consolidates knowledge from existing scientific advances and investigates scientific gaps associated with the vapor intrusion preferential pathway conceptual model (i.e. conduit vapor intrusion), associated with the vapor entry pathway into buildings via sewer systems. The overall goal of this …

An Investigation Of The Legitimacy Of The Underlying Assumptions Of The Scs Curve Number Method By Application To Actual Urban Watersheds, Robert K. Peterson

Theses and Dissertations--Civil Engineering

The Soil Conservation Service (SCS) Curve Number (CN) method is widely used to estimate direct runoff, and its TR-55 urban-adapted Curve Numbers are commonly applied in stormwater design. However, the underlying assumptions of the method have been the subject of contemporary review, and concerns remain that these values underestimate runoff in actual urban watersheds. This study evaluates the performance of TR-55 CNs using rainfall–runoff data from twenty real-world urban watersheds in the National Stormwater Quality Database.

Empirical Curve Numbers were derived using two calibration techniques, the asymptotic CN method (CN∞) and a nonlinear least-squares optimization method (CN_LS), and …

Earthquake Wrangler: Leveraging Ios Technology For Earthquake Detection And Early Warning Application To Enhance Public Safety., Luis F. Salome

Theses and Dissertations--Civil Engineering

Earthquakes are devastating natural phenomena and generate secondary hazards such as tsunamis, landslides and fires. Their catastrophic impacts span both developed nations including the United States, Japan, Turkey, and Italy and developing countries such as El Salvador, Haiti, Nepal and the Philippines, where disparities in early warning infrastructure remain important. Seismic events start with stress waves generated by tectonic plate motion, with body waves (P- waves and S-waves) and surface Rayleigh and love waves that carry energy through the earth. While some regions have adopted advanced early warning systems based on seismic hazard models and strong ground motion analysis, others …

Harmful Algal Bloom Prediction Modeling In The Face Of A Changing Climate, Jordan E. Spears

Theses and Dissertations--Civil Engineering

Harmful algal blooms (HABs) in rivers pose significant threats to drinking water quality and public health, yet the predictive understanding of their proliferation remains limited, particularly regarding the influence of flow conditions in large rivers. This thesis addresses the critical knowledge gap of the relationship between seasonal flow variability and HAB proliferation in the Ohio River, with the Markland Pool serving as the primary study site. This study quantified the impact of early summer high flow events (>7500 m³ s^-1) and late summer to early fall low flow conditions (< 1500 m³ s^-1) by integrating …

Simplified Molecular Diagnostics Methods For Environmental Testing Of Pathogens And Other Applications, Mohammad Dehghan Banadaki

Theses and Dissertations--Mechanical and Aerospace Engineering

Environmental Surveillance (ES) has emerged as a powerful tool to monitor the emergence and persistence of a pathogen within a facility or community using wastewater/water analysis. Over the past four years, implementation of ES has experienced an explosive acceleration, driven by efforts to monitor the spread of SARS-CoV-2, which has made ES a routinely used public health tool in many locations. We can now use ES to measure the emergence/presence/abundance of different viruses (e.g., SARS-CoV-2, influenza, mpox), bacteria (e.g., E. coli, V. cholerae, antibiotic-resistant strains), fungi (e.g., C. auris), and other biological markers indicative of infectious diseases. However, its broad …

Quantifying Sedimentation Dynamics Of Regulated River Backwater Confluences With Low-Order Tributaries, Abby Kathryne Berry

Theses and Dissertations--Biosystems and Agricultural Engineering

Sediment dynamics in backwater confluences of regulated rivers have received limited study, despite being recognized as hotspots for sedimentation and nutrient attenuation. Development of management and restoration strategies in these landscapes require improved understanding of fluvial geomorphology and sediment transport dynamics due to the alterations in hydraulic regimes and sediment inputs associated with riverine backwaters. The objective of this study was to couple remote sensing, high frequency sensing, and numerical modeling to quantify drivers of erosion and deposition dynamics within regulated river backwater tributary confluences. To meet the objective of this study, data was collected and analyzed from the Fourpole …

Establishing Performance Criteria For Evaluating Watershed-Scale Sediment And Nutrient Models At Fine Temporal Scales, Aayush Pandit, Sarah Hogan, David Tyler Mahoney, William I. Ford, James F. Fox, Christopher Wellen, Admin Husic

Civil Engineering Faculty Publications

Watershed water quality models are mathematical tools used to simulate processes related to water, sediment, and nutrients. These models provide a framework that can be used to inform decision-making and the allocation of resources for watershed management. Therefore, it is critical to answer the question “when is a model good enough?” Established performance evaluation criteria, or thresholds for what is considered a ‘good’ model, provide common benchmarks against which model performance can be compared. Since the publication of prior meta-analyses on this topic, developments in the last decade necessitate further investigation, such as the advancement in high performance computing, the …

Economic Contribution Of Kentucky Airports, P. Gayle Marks, Bethany Paris, Bryan Gibson

Kentucky Transportation Center Research Report

Airports generate economic impacts that are felt well beyond their physical boundaries by supporting commerce, tourism, and the provision of essential services. To understand the economic contributions of airports throughout Kentucky, researchers collected data from general aviation (GA) airports and commercial service (CS) airports across the state on operational statistics, levels of employment, and usage patterns in calendar year 2022. IMPLAN^® econometric models were developed to estimate the economic contributions of the state’s airports. These models show that in 2022 Kentucky’s airports contributed $23.7 billion in total economic output, which equals 9.1 percent of its gross domestic product ($261.5 …

Improving Transportation Resiliency, Ben Blandford, Erin Lammers-Staats, Emma Gregory

Kentucky Transportation Center Research Report

Transportation agencies are increasingly more challenged by the effects of extreme weather and national hazards on transportation assets.  Severe weather events in Kentucky have become more frequent and more costly. These extreme events damage transportation assets, increase maintenance costs and strain transportation budgets. Climate models predict changing conditions to occur over the next century that differ from historical data. In Kentucky, models predict a warmer and wetter environment. The goal of this research is to help KYTC plan for extreme weather and natural hazards events, as well as absorb, recover from, and adapt to the resulting damage.  Researchers determined where …

Evaluation Of Kentucky’S Driver Focus Camera System, David Leddy, Brian Beaven, Xiaobing Li, Andrew Martin, Jennifer Walton, Chris Van Dyke

Kentucky Transportation Center Research Report

Commercial motor vehicle (CMV) drivers who engage in federally prohibited activities such as not wearing safety belts, using hand-held mobile phones, or texting while driving endanger themselves and imperil the well-being of everyone who occupies the surrounding roadway environment. Unfortunately, conventional CMV inspection routines fail to detect many of these violations because inspectors have difficulty obtaining a clear view of truck cab interiors from inspection facilities. Recognizing it is critical to improve enforcement of Federal Motor Carrier Safety Regulations, this project evaluated the performance of a Driver Focus Camera System (DFCS) at an inspection facility on Interstate 75 northbound in …

Kentucky Traffic Collision Facts Calendar Year 2023 Report, Paul Ross, Eric Green, Chris Blackden, Kenneth R. Agent, Chris Van Dyke

Kentucky Transportation Center Research Report

No abstract provided.

Analysis Of Traffic Crash Data In Kentucky 2019-2023, Paul Ross, Eric Green, Chris Blackden, Christopher Van Dyke, Teng Wang, Mohammad Majidi

Kentucky Transportation Center Research Report

No abstract provided.

2024 Safety Belt Usage Survey In Kentucky, Erin Lammers-Staats, Derek Young, Kenneth R. Agent

Kentucky Transportation Center Research Report

No abstract provided.

Spot, Zone And Overcoat Painting Of Steel Bridges, Christopher Goff, Sudhir Palle

Kentucky Transportation Center Research Report

Over the past 25 – 30 years, the Kentucky Transportation Cabinet (KYTC) has replaced lead-based coatings on many bridges, often with zinc-based systems. But many of these coating systems are now degrading and reaching the ends of their service lives. Historically, KYTC has relied entirely on remove-and-replace painting, however, given the programmatic costs associated with remove-and-replace painting and constraints imposed by limited funding, the agency needs to explore more economical options, such as spot, zone, and overcoat painting. This report discusses use cases for spot, zone, and overcoat painting and lays out guidelines staff can use to determine what method …

Evaluation Of Roadway Reconfigurations In Louisville, Kentucky, William Staats, Adam Kirk

Kentucky Transportation Center Research Report

In 2009, Louisville Metro Public Works undertook its first roadway reconfiguration project, converting a section of Eastern Parkway (US 60A) from a four-lane undivided road to a three-lane section with a two-way left-turn lane and one travel lane in each direction. Since this initial project, Louisville Metro Public Works and the Kentucky Transportation Cabinet (KYTC) have completed 40 roadway reconfigurations to reduce the number of through lanes and reassign existing right-of-way to other roadway users. Additionally, the agencies have 25 more planned or proposed reconfiguration projects. This report documents the safety and operational performance of reconfigured roads. Across all projects, …