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The I-81 Corridor in Virginia traverses the western part of the state, connecting Bristol in the south to Winchester in the north. A study carried out at the Virginia Tech Center for Transportation Research identified traffic safety, work zone safety and traffic control, trucking issues, and intercity traveler information needs as important issues that deserve attention on the I-81 Corridor in Virginia. Analysis of work zone accident statistics showed a need for real-time systems to enhance work zone safety. Real-time advanced warning and traffic control systems provide a means of dynamic information dissemination and advanced warning, thereby enhancing work zone safety and facilitating traffic control. The focus of this research was on the development of functional and system requirements for a real-time advanced warning and traffic control system for work zones. This task was based on the examination of work zone accidents and their causes. The functional requirements include advanced warning, surveillance, advisory, and control functions. Each of these functions consists of several sub-functions. The needs with respect to each of these functions have also been identified. System requirements such as real-time operation, credibility, portability, ease of installation, and adaptability were also identified. Evaluation criteria and potential Measures Of Effectiveness (MOEs) for the evaluation of the system were also identified. Additionally, issues related to the evaluation of the system, such as time duration for evaluation and data collection techniques were identified and examined. / Master of Science

This thesis seeks to provide guidance on the deployment of Bluetooth sensors for travel time measurement in work zone corridors. The investigation focuses on the detection characteristics of Class 1 and Class 2 Bluetooth devices, and how cultivating an understanding of these characteristics together with the effect of the sensor inquiry cycle length can suggest a more precise method of travel time measurement. This thesis also explores the range of detection location around a Bluetooth sensor in order to recommend a minimum corridor separation of Bluetooth sensors, and to ascertain the best method of Bluetooth travel time derivation. Finally, this thesis investigates these principles further through multiple side-fire deployments on the I-285 corridor in Atlanta, Georgia; as well as two deployments capturing several hours of active work zone travel time.

Baigiamajame darbe buvo atlikta mokslinių darbų analizė darbo zonų tematika. Pateikiamos pagrindinės darbo zonos atsiradimo priežastys. Kelio darbo vietos suklasifikuotos pagal keletą kriterijų ir aprašomos darbo zonų valdymo galimybės. Darbe išskiriamos dvi pagrindinės darbo zonų problemos: eismo saugumo ir transporto priemonių intensyvumo. Analizuojamos darbo zonų spūsčių automobilių keliuose sukeliamos problemos. Darbe pateikiami transporto priemonių intensyvumo pagrindiniai parametrai ir veiksniai, turintys jiems įtakos. Atlikti eksperimentiniai tyrimai pasirinktose darbo zonose ir gauti rezultatai apibendrinami. Darbo apimtis – 72 psl. teksto be priedų, 39 iliustr., 12 lent., 26 bibliografinių šaltinių. / The final work was carried out research work analyzes the work zone topics. Contains the main work area causes. Multiple jobs are grouped according to several criteria and a description of the work zone management capabilities. The paper distinguishes between two areas of work problems: traffic safety and transport intensity. Analyzed areas of work on the roads caused congestion problems. The paper presents the vehicle parameters and the intensity of the main factors influencing them. Tests were performed in selected areas of work and the results obtained are summarized. Thesis consists of: 72 p. texts without appendixes, 39 pictures, 12 tables, 26 bibliographical entries.

While regular maintenance of roads and bridges are essential to ensure a high level of service for road users, road users typically do not prefer having to drive through a construction zone because of the lower speed and increased possibilities of crashes. These road user inconveniences are typically ignored or not given much weight while planning, developing, and awarding construction and maintenance projects. Typically, a contractor with the lowest bid is awarded a construction project irrespective of whether the project will be completed in a shorter or longer duration if the duration is within a provided limit. Such a decision-making process, known as "the apparent lowest bidder," is the most common method for selecting the best contractor for construction projects, even though quicker completion of a construction project results in reduced inconvenience to the road users. To overcome this limitation, state Departments of Transportation (DOTs) have started to use the monetary quantification of the road user inconveniences, known as the road user cost, while selecting the best contractor for a project. However, monetary quantification of the road user cost is a significant challenge to state DOTs. Many state DOTs lack a systematic methodology to compute the road user cost or have inconsistent methodologies within the same state DOT. Currently, the Tennessee Department of Transportation (TDOT) does not have a systematic methodology to compute the road user cost. This study aims to review existing methodologies from other state DOTs across the U.S. to identify the best practices for calculating the road user cost. To achieve this, the study reviewed existing literature on the subject and conducted a nationwide survey questionnaire covering all 50 state DOTs. The survey result shows that 34 out of 37 responding state DOTs are currently calculating the road user cost. More than half of the state DOTs have developed their state-specific methodologies for various purposes, including A+B contract evaluation, incentives/disincentives determination, and benefit-cost analysis for alternative project evaluation. The delay cost and the vehicle operating costs are the two most common components to compute the road user costs. As the road user cost calculation requires additional time and effort, it is calculated only for a limited number of construction projects based on the project's duration, location, and complexity. Most state DOTs prefer and use a spreadsheet-based tool to ease the calculation process. The survey results provide the most extensive and detailed information about the current practices of calculating the road user costs in the U.S. The survey results will be used to develop a new methodology to compute road user costs for TDOT. Other state DOTs can also use the study's findings to improve their road user cost calculation methodologies. Such improved methodology will help state DOTs make more informed contract-management decisions and reduce inconveniences to road users. Keywords: Road User's Cost, Department of Transportation, Work Zone, A+B Bidding

Freeway work zones with lane closures can adversely affect mobility, safety, and sustainability. Capacity drop phenomena near work zone areas can further decrease work zone capacity and exacerbate traffic congestion. To mitigate the negative impacts caused by freeway work zones, many variable speed limits (VSL) control methods have been proposed to proactively regulate the traffic flow. However, a simple yet robust VSL controller that considers the nonlinearity induced by the associated capacity drop is still needed. Also, most existing studies of VSL control neglected the impacts of traffic sensor failures that commonly occur in transportation systems. Large deviations of traffic measurements caused by sensor faults can greatly affect the reliability of VSL controllers. To address the aforementioned challenges, this research proposes a fault-tolerant VSL controller for a freeway work zone with consideration of sensor faults. A traffic flow model was developed to understand and describe the traffic dynamics near work zone areas. Then a VSL controller based on sliding mode control was designed to generate dynamic speed limits in real time using traffic measurements. To achieve VSL control fault tolerance, analytical redundancy was exploited to develop an observer-based method and an interacting multiple model with a pseudo-model set (IMMP) based method for permanent and recurrent sensor faults respectively. The proposed system was evaluated under realistic freeway work zone conditions using the traffic simulator SUMO. This research contributes to the body of knowledge by developing fault-tolerant VSL control for freeway work zones with reliable performance under permanent and recurrent sensor faults. With reliable sensor fault diagnosis, the fault-tolerant VSL controller can consistently reduce travel time, safety risks, emissions, and fuel consumption. Therefore, with a growing number of work zones due to aging road infrastructure and increasing demand, the proposed system offers broader impacts through congestion mitigation and consistent improvements in mobility, safety, and sustainability near work zones. / Thesis / Doctor of Philosophy (PhD) / Freeway work zones can increase congestion with higher travel time, safety risk, emissions and fuel consumption. This research aims to improve traffic conditions near work zones using a variable speed limits control system. By exploiting redundant traffic information, a variable speed limit control system that is insensitive to traffic sensor failures is presented. The proposed system was evaluated under realistic freeway work zone conditions in a simulation environment. The results show that the proposed system can reliably detect sensor failures and consistently provide improvements in mobility, safety and sustainability despite the presence of traffic sensor failures.

No-lane closure workzone is typical during the construction of open road tolling lanes of a toll plaza. The influence of no-lane closure on toll plazas' performance is unknown because very few studies have been conducted to address this topic. The open road tolling (ORT) has become the new trend of operating an efficient toll plaza. So, the upgrading of a toll plaza from gated E-pass to open road E-pass has become common. The better the toll plaza authority knows about the influence of this construction and congestion effects, the better it can serve the costumers. This project mainly deals with the effects of no-lane closure workzone on the toll plaza performance, and with the collected data, a model was developed predicting 15 minutes throughput and queue length. To better study the workzone impact on toll plaza performance, three sites with different characteristics were selected. They are Lake Jesup Mainline Plaza along the Seminole Expressway (SR-417), the Beachline West Expressway Toll Plaza along the SR-528 and Conway toll plaza along the Holland East-West Expressway (SR-408) in Orlando area of Central Florida. Data preparation includes demand, throughput, processing rates, and queue lengths of different toll categories. Data was collected during peak period for before and during the no-lane closure construction (phase 1) at SR-528 and Lake Jesup toll plaza at SR-417, and middle lane construction (phase 2) and after opening ORT lanes (phase 3) at Conway toll plaza at SR-408.Comparisons were conducted between non-construction stage and construction stage for non-lane closure workzone effects study using data from 417 and 528, and comparisons between middle-lane-construction and complete of construction stage for ORT impact study using data from 408. Analysis results showed that when the toll plaza is operating at or close to its capacity, the no-lane closure workzone can have a negative impact on its performance. But when the toll plaza's demand is lower than the capacity, the no-lane closure workzone has no impact at the toll plaza's performance. And the ORT lanes have a positive influence on the capacity and throughput of the toll plaza. After the impact of no-lane closure workzone on toll plaza has been analyzed, all the data from three toll plazas are put together and a model is built using the variables of Demand/Capacity ratio, percentage of each category of vehicles, E-pass, Automatic or Manual, number of Manual lanes, workzone or no-workzone. Throughput and Queue length can be predicted by this model.

<p>Cell phone use while driving is one of the commonest distracted driving behaviors that causes fatal crashes, and drivers are more likely to use their cell phones in work zones because of slow-moving traffic. The road safety campaign literature suggests that persuasive messages can positively influence safe driving behaviors leading to a reduction in crashes. Thus, this dissertation, guided by the risk perception attitude (RPA) framework, sought to examine how tailored messaging could serve as an effective communication strategy to promote positive attitudes and behavioral intentions in the context of cell phone use avoidance while driving through highway work zones. Findings from two studies, using a college student sample and a national sample of US young adults between 18 and 24 years old, revealed that the RPA framework likely does not serve as a useful audience segmentation strategy in this context because an overwhelming majority of participants (about 87%) belonged to the responsive group. A tailored messaging approach did not influence cell phone use avoidance while driving attitudes and intentions among the young adults because the majority of participants (70%) felt the messages were not designed uniquely for them and might not be personally relevant to them. However, the majority of participants (62%) reported that highway work zone safety was an important topic they would want to receive future messaging about because messages about this topic would help to save lives and protect public safety, drastically reduce crashes in highway work zones, and promote safe driving behaviors in highway work zones. Participants who were aware of the existence of state laws banning cell phone use while driving reported slightly higher attitudes toward and intentions to engage in safe driving behaviors compared to those who were not aware of the existence of such state laws. This dissertation suggests that instead of creating messages to raise risk perceptions and enhance efficacy perceptions, informing the young adult population in the US about the existence of laws banning cell phone use while driving might be an effective means to discourage them from using their cell phones while driving through highway work zones. By extending the RPA framework as an audience segmentation strategy, this dissertation also proposes a responsive group classification framework which could serve as a useful audience segmentation strategy in this study context to classify audiences into four groups to effectively tailor messages to them.</p>

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