Roy Sturgill

Accuracy analysis of selected tools for estimating contract time on highway construction projects

In many highway construction projects, the time available to complete construction is set by the contract documents. Most transportation agencies have developed tools to assist project planners in estimating the amount of time required to complete the project, but how accurate are these systems in estimating project duration? The current work examines the accuracy of integrated scheduling systems from two state transportation agencies in estimating contract time for previously completed Kentucky highway construction projects. The accuracy of the systems where tested against project data from 66 completed Kentucky Transportation Cabinet Projects. The analysis revealed that the average accuracy of both systems in predicting project duration was greater than ±200% across a variety of projects. A pilot study of the use of multivariate regression analysis of the data from 66 completed Kentucky Transportation Cabinet projects was performed to identify specific combinations of work item quantities with the engineers cost estimate that produce the most accurate estimate of project duration. The accuracy of the developed regression equation in predicting highway construction project duration was ±25%. The current work contributes improved understanding of the accuracy of integrate scheduling systems in predicting highway construction duration.

Visually improving construction contract administration

The construction industry runs into many claim and dispute issues. Often these can be associated with the contractual conditions. What if the conditions themselves or the people writing them are not causing the problems? The blame may fall on the actual reading of the complex conditions and the inability of the human brain to comprehend all the information read. The field of psychology can be used to support this claim as well as to support the potential solution of use of flowcharts to illustrate contract conditions. The flowcharts provide a visual framework to complement and organize the text of the conditions. A project was designed with the Virginia Department of Transportation and the Virginia Polytechnic Institute and State University to collaborate and investigate flowchart usage. Flowcharts depicting general conditions were produced, and the outcomes of the project support the claim that a greater understanding can be achieved with the creation and use of flowchart-based conditions complementing the text format.

Towards an Automated Asphalt Paving Construction Inspection Operation

Collecting load tickets is an example of an antiquated practice that puts inspectors in harm’s way either adjacent to traffic, in close proximity to moving or backing equipment, or at times requires climbing onto trucks to reach tickets. Technology exists to collect this information electronically allowing for safer, efficient inspection methods. Departments of Transportation are charged with inspecting an increasing work load with a diminishing number of inspection staff. Recently, doing more with less has led to the prioritization of inspection activities and resulted in less collection of data and visual inspection on projects. Technology advancements are available to improve data collection and provide for more efficient inspection. Using GPS and GIS technology tied into electronic scale report-out systems, a fleet tracking system traces haul routes, reports travel time and tonnage, and even assists contractors with equipment matching and balancing. Data from this system coupled with other technologies remote monitoring of temperature, intelligent compaction, and network enabled cameras provide an opportunity to enhance inspection and increase construction inspection productivity all the while enriching detail of project records. Challenges to the system include connectivity, interoperability, and usability. The contribution of this paper is to provide a framework in which to combine these commercially available technologies into a multi-faceted, enhanced inspection approach.

Developing a Pre-Task Safety Briefing Tool for Kentucky Maintenance Personnel

The dangerous work environment in the construction industry and the inherent high risks associated with its work make it the focus of safety training and regulations. Highway construction and maintenance has unique hazards but seemingly less directly applicable safety standards, regulations, and programs. Department of Transportation (DOT) employees working in highway maintenance are exposed to a variety of unique hazards specifically associated with their work and not relating to the adjacent traffic. Highway site safety does not receive sufficient attention in terms of safety research and programs. As part of the efforts of the Kentucky Transportation Cabinet (KYTC) to improve safety for their employees, this paper describes the data-driven design of a pre-task safety briefing tool. By analyzing previous incident data of KYTC maintenance workers and identifying frequent hazards present within their typical work operations and the reasons behind such hazards, the final product of this study is a tool that is relatable and relevant to KYTC maintenance workers. The tool presents these hazards along with the associated reasons and the appropriate safety practices to avoid or mitigate the associated risk. The data analysis of this study highlighted that human factors and ergonomics play a significant role in the injuries related to the subject population, yet there is little guidance or standards for addressing these factors. The goal of this safety tool is to improve the safety performance of KYTC maintenance crews by increasing workers’ safety awareness.

Estimating Earthwork Volumes Through Use of Unmanned Aerial Systems

Unmanned aerial systems (UASs) and unmanned aerial vehicles (UAVs) have become increasingly attractive for numerous surveying applications in civil engineering, agriculture, and many other fields. The unmanned systems and vehicles are capable of performing photogrammetric data acquisition with equipped digital cameras that allows for converting images to highly precise, georeferenced three-dimensional models. However, more studies are needed to demonstrate practical applications of UAS systems and UAVs on construction sites. In this project, UAS systems and UAVs and digital photogrammetry technology are introduced to estimate the earthwork volume of a highway extension project. The georeferenced images were processed by the photogrammetry software, Pix4Dmapper, which is a tool for converting images into an accurate and applicable three-dimensional point cloud model. Progress models were created over the course of several weeks. The volume of earth was computed by comparing the point cloud of the progress models after model processing. To ensure reliability, the accuracy of the UAS and UAV photogrammetry was verified by comparison with conventional ground survey methods and the results from different flights. The project presents the feasibility and effectiveness of using UAS systems and UAVs in estimating earthwork volumes on the basis of the results of an accuracy test and the efficiency of the survey.

Modeling Long-Term Highway Staffing Requirements for State Transportation Agencies

State transportation agencies (STAs) across the country face many challenges in repairing and enhancing highway infrastructure to meet rapidly increasing transportation needs. One of these challenges is maintaining an adequate and efficient agency staff. To effectively plan for future staffing levels, STAs need a method for forecasting long-term staffing requirements. However, the methods currently in use cannot function without well-defined projects; therefore, making long-term forecasts is difficult. This paper seeks to develop a dynamic model that captures the feedback mechanisms within the system that determines highway staffing requirements. The system dynamics modeling method was used to build the forecasting model. The formal model was based on dynamic hypotheses derived from a literature review and interviews with transportation experts. Qualitative and quantitative data from literature and federal and state databases were used to support the values and equations in the model. The model integrates STAs’ strategic plans, funding situations, and staffing strategies and determines future staffing levels and will hopefully fill the absence of long-term forecasting tools at STAs. Standard system dynamics validation procedures were used to test the model, after which input data specific to the Kentucky Transportation Cabinet were used to calibrate the model and to simulate an expected retirement wave and search for solutions to address temporary staffing shortages.

Streamlined Project Closeout for Construction at KYTC

Project closeout is the period between the end of construction and when a contract is finalized. During closeout, resources are held in encumbered funds intended for the project and in the contractor’s bonding capacity. Although the Kentucky Transportation Cabinet’s (KYTC) stated goal is to close out projects within 240 days of their ending, in 2016 the average duration of project closeout was 366 days. This report analyzes the Cabinet’s project closeout procedures, summarizes project closeout best practices adopted by other state transportation agencies, and recommends ways to improve KYTC’s practices. Streamlining project closeouts would free up sufficient funds to resurface approximately 2,000 to 7,000 total lane miles that would otherwise not be rehabilitated. To begin reforming project closeout, the Cabinet may benefit from 1) investigating ways to improve the preparation of final documentation and 2) reducing the amount of time allocated for development and completion of the materials check. Other recommendations for revamping project closeout include establishing a KYTC task force to conduct high-level analysis of the project closeout process; thoroughly implementing e-Construction methodologies, which can reduce paperwork and centralize record-keeping within tightly controlled and monitored databases; revising project closeout checklists to standardize the process and eliminate all steps that are unneeded or outdated; and optimizing project closeout processes at the district level to help personnel adopt best practices. More efficient project closeouts will benefit the public because of their potential to increase the amount of funding that can be dedicated to critical transportation projects that would otherwise remain unaddressed. As the Cabinet investigates ways to begin this process, it is important to keep in mind that strategies or methods for streamlining project closeout should be implemented by KYTC personnel, as this increases the likelihood that staff buy-in across the agency.

Estimating Constructability Review Benefits for Highway Projects

Constructability review is a process used in the design phase of a project in order to interject construction knowledge and address potential issues prior to construction. This typically occurs with a team or panel of constructability reviewers. Current staffing and budgetary constraints have resulted in state transportation agencies being very careful about disturbing the existing project development process with practices that seemingly lie outside the main process, such as constructability review. An issue that constructability reviews face is the lack of any documented savings. Over the past decade, the Kentucky Transportation Cabinet has streamlined the constructability review process by relying on a smaller team or single reviewer per project and recently taken on an effort to estimate monetary benefits from such reviews. This paper discusses the evaluation of constructability reviews at the project level by comparing change order percentages on projects reviewed versus those not being reviewed. This approach showed a clear indication that there are monetary savings associated with constructability reviews resulting in a conservative savings estimate of 1.25 percent of the project cost without including the additional inherent savings in time, lessons learned or other aspects not readily quantifiable. This evidence presents that a streamlined constructability review process and team can still provide savings to a project. A regression model was also developed in this work to estimate the potential monetary gains from the constructability review comments but additional analysis is needed to improve accuracy. There is potential that this model could be used to further streamline the process by identifying and focusing on projects where constructability review savings could be maximized.

Predictive Risk Modeling of Differential Bridge Settlement

Differential settlement between the roadway pavement resting on embankment fill and the bridge abutment built on more rigid foundation often creates a bump when driving from roadway to bridge, and vice versa. This paper studies the problem at a macroscopic level by determining a method to predict the levels of approach settlement to assist designers in developing remediation plans during project development to minimize the lifecycle costs of bridge bump repairs. A macro method considering a combination of maintenance times, maintenance measures, and observed settlement was used to classify the differential settlement scale as minimal, moderate, and severe. A set of project characteristics including approach, abutment type, embankment, foundation, and traffic volume that may influence the formation of differential settlement were identified and used as parameters to develop a model to predict the settlement severity for a given approach. Logistic regression analyses were implemented to identify the relationships between the levels of differential settlement and the input variables for a sample of 600 randomly selected bridges in Kentucky. Geographic region, approach age, average daily traffic, and the use of approach slabs are identified as the four most predominant factors that can significantly affect the formation of differential settlement. Based on the performance of bridge approaches in Kentucky, how those parameters interacted in the prediction model is illustrated in the logistic regressions.

Using Parametric Modeling to Estimate Highway Construction Contract Time

Federal regulations require that state transportation agencies have written procedures for setting the construction contract time for highway projects. Since the institution of those regulations, state agencies have used a variety of methods to estimate and set contract time. FHWA recommends the use of methods based on production rate and activity precedence and logic in this process. For years, the Kentucky Transportation Cabinet used a system based around these requirements and recommendations only to find that the system produced estimates varying widely from actual construction times. The use of parametric modeling and historic contract times produced a system that more accurately estimates contract times and with an associated Microsoft Excel–based tool is more user friendly. This approach used project cost and bid item quantity data in multivariate regression–based modeling to develop a set of equations that provide the Kentucky Transportation Cabinet with contract time estimates for projects in a matter of minutes by using data readily available at later design stages.