Research conducted over the past three years in the Vehicle Analysis and Simulation Laboratory at Virginia Tech has resulted in the development and validation of algorithms for the detection of driver drowsiness. Specifically, the goal of the research has been to develop the best possible drowsiness-detection algorithms using measures that can be computed while a vehicle is in motion with minimal interference with the driver. The results of these studies, which have been previously reported, generally support the feasibility of drowsy-driver detection and indicate that further analysis and refinement of the algorithms is warranted. This thesis researches several methods of refining existing driver-status algorithms, the integration of driver-performance deterioration measures, and the selection of appropriate alarm thresholds to be used in test and evaluation study. The results of five algorithm optimization refinements are described. Chapter 2 reports that the elimination of outlier dependent measure data prior to algorithm development was found not to improve algorithm accuracy. Chapter 3 describes that the addition of cross product and squared terms to the algorithms did not provide consistent improvement in algorithm accuracy. Chapter 4 reports that, although time-on-task variables were found to have some improved capability, they did not consistently add to the accuracy of the algorithms. / Master of Science

This research presents theoretically an automated vehicle merging control which is an important subsystem of AHS. The goal of the system is to automatically control the vehicle merging from ramp to the AHS lane in an efficient, smooth and safe manner. The entire merging process is divided the a speed adjustment stage and a lane merging stage. Three important parameters; acceptability, availability and pursuability are analyzed to characterize the AHS lane gap features. Three control guidance laws (linear, optimal and parabolic speed profile) are developed to describe the desired behaviors of the merging vehicle based on the merging quality and safety consideration. The desired states of the merging vehicle are generated through the outer loop by specified control guidance law. The tracking errors compared with desired states are eliminated by the proper design of controllers in the inner loop. Both longitudinal and lateral controller are designed using the sliding mode control theory which can handle the model nonlinearities and uncertainties of the vehicle dynamics. Two new sliding mode methods are proposed in the design of the lateral controller. The proposed system is evaluated and validated through computer simulations. The simulation results show that system performance is satisfactory under the various merging conditions for a smooth, efficient and safe merging. The system also supplies a basis for the further research on the multiple merging control system and the lane changing control system. / Ph. D.

Master of Science / Department of Civil Engineering / Sunanda Dissanayake / Although extensive research has been conducted on urban freeway capacity estimation methods, minimal research has been carried out for rural highway sections, especially sections within work zones. This study filled that void for rural highways in Kansas. This study estimated capacity of rural highway work zones in Kansas. Six work zone locations were selected. An average of six days’ worth of field data was collected, from mid-October 2013 to late November 2013, at each of these work zone sites. Two capacity estimation methods were utilized, including the Maximum Observed 15-minute Flow Rate Method and the Platooning Method divided into 15-minute intervals. The Maximum Observed 15-minute Flow Rate Method provided an average capacity of 1469 passenger cars per hour per lane (pcphpl) with a standard deviation of 141 pcphpl, while the Platooning Method provided a maximum average capacity of 1195 pcphpl and a standard deviation of 28 pcphpl. Based on observed data and analysis carried out in this study, the recommended capacity to be used is 1500 pcphpl when designing work zones for rural highways in Kansas. This research provides the proposed standard value of rural highway work zone capacities so engineers and city planners can effectively mitigate congestion that would have otherwise occurred due to impeding construction/maintenance.

The transportation system is vital to the nation’s economic growth and stability, as it provides mobility for commuters while supporting the United States’ ability to compete in an increasingly competitive global economy. State Transportation Agencies across the country continue to face many challenges to repair and enhance highway infrastructure to meet the rapid increasing transportation needs. One of these challenges is maintaining an adequate and efficient agency staff. In order to effectively plan for future staffing levels, State Transportation Agencies need a method for forecasting long term staffing requirements. However, current methods in use cannot function without well-defined projects and therefore making long term forecasts is difficult. This dissertation seeks to develop a dynamic model which captures the feedback mechanisms within the system that determines highway staffing requirements. The system dynamics modeling methodology was used to build the forecasting model. The formal model was based on dynamic hypotheses derived from literature review and interviews with transportation experts. Both qualitative and quantitative data from literature, federal and state database were used to support the values and equations in the model. The model integrates State Transportation Agencies’ strategic plans, funding situations and workforce management strategies while determining future workforce requirements, and will hopefully fill the absence of long-term staffing level forecasting tools at State Transportation Agencies. By performing sensitivity simulations and statistical screening on possible drivers of the system behavior, the dynamic impacts of desired highway pavement performance level, availability of road fund and bridge fund on the required numbers of Engineers and Technicians throughout a 25-year simulation period were closely examined. Staffing strategies such as recruiting options (in-house vs. consultants) and hiring levels (entry level vs. senior level) were tested. Finally the model was calibrated using input data specific to Kentucky to simulate an expected retirement wave and search for solutions to address temporary staffing shortage.

Only circumscribed aspects of highway aggression have been investigated. The upsurge of abuse and violence transpiring between motorists necessitated a more definitive depiction of the actual events, participants, and relevant contextual features. A questionnaire administered to 120 motorists, aged 18 to 68, solicited a recountal of incidents occurring within 12 months and a description of their most recent encounter. Based on severity of experience, subjects were relegated to distal threat, direct threat, and nonvictim groups. Although most events involved unreported distal threats lasting less than three minutes, men and non-college graduates were more often directly threatened, while non-victims were predominantly women and college graduates. Perpetrators were primarily unknown Caucasian males who generally aggressed in populated areas during afternoon hours.

A proper understanding of the local construction market is essential for making appropriate project budgeting and planning decisions. State highway agencies typically use highway construction cost indexes (HCCIs) to understand the current market conditions. In the U.S. highway construction industry, the Federal Highway Administration (FHWA) pioneered the concept of a HCCI as an indicator of the national construction market. State Departments of Transportation (DOT) also started developing their state level HCCIs to better represent their state level construction markets. But, some state DOTs noted the lack of guidance to develop and update their HCCIs. This paper summarizes literature review and nationwide questionnaire survey results to identify the current practices of calculating and using HCCIs. There are two methods to generate basket of construction items for HCCI calculation: a) categorized market basket and b) item level market basket. The Fisher index is the most popular indexing formula among the state DOTs and is also recommended by the FHWA and International Monetary Fund (IMF). Despite many potential users of HCCIs, the current use of HCCIs is very limited in state DOTs.

An examination was conducted of the potential of proposed highway construction for serving the needs and interests of the population of the Canyonlands Region of southeastern Utah. The history of the highway development issue in the region was first examined with special attention given to the local position on the issue as expressed by local government spokesmen. Next, the total system of development proposals for the region was divided into four sections using criteria of area served and degree of controversy. A map analysis was conducted to determine how these four separate proposals would serve transportation needs of the region. Travel data for 1971 Utah nonresident travelers were utilized to determine present tourism travel and expenditure patterns within the region. Projections were made as to how these patterns would be altered by the four proposals and of how such alterations would affect the tourism industry in the five Canyonlands counties. Region resident perceptions of how the proposals would serve transportation, tourism development, and general economic needs of the region, its counties, and communities were obtained from 231 questionnaires. The same instruments also examined resident preferences for route development. The analyses indicated that the proposed developments will have few effects on regional transportation needs, and that the impact on the tourism industry will be substantial in some areas within the region and negligible in others. Resident expectations of which proposals would best meet county, community, and household needs were generally realistic. Residents assigned priority for development to proposals anticipated to best serve needs at these levels. Regional needs were not clearly perceived and were not important in determining development preferences. The position on the highway development issue taken by local government leaders distorts the views of residents but does so in a way which generally serves the local interest.

Thesis (M.A.)--University of Alberta, 2010. / Title from pdf file title screen (viewed on January 6, 2010). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Arts, Comparative Literature." Includes bibliographical references.

The Texas Department of Transportation has been experiencing budget fluctuations in the recent past. These budget fluctuations can have a pronounced effect in the agency’s highway maintenance operations if key maintenance activities must be delayed due to budget constraints. The methodology proposed in this research project aims at reducing the impact of budget fluctuations on highway maintenance by identifying and ranking maintenance activities based on a set of identified maintenance objectives. With the help of maintenance experts from the highway agency, four maintenance objectives were identified and considered for this research project: include Aesthetics, Safety, System Operations and System Preservation. A similar process was conducted to identify the most relevant maintenance activities from a list of over 120 different maintenance functions used by the Texas Department of Transportation. The original list of maintenance functions was reduced by combining similar sub-categories. Ultimately, 16 maintenance functions were identified and included in this research project, representing an average of over 75 percent of the agencies maintenance expenditures between fiscal years 2008 – 2010. These four maintenance objectives and sixteen maintenance functions were then evaluated by maintenance experts from different geographic locations of the state using the Analytical Hierarchy Process to produce an Overall Relative Weight for each maintenance function. This process allowed each evaluator’s judgments and preferences to influence the final weight values and rankings of the maintenance functions. The Overall Relative Weight corresponds to each maintenance sub-category’s component from each maintenance objective and can be defined as the performance risk of not carrying out the maintenance activity. This information can be used by maintenance engineers and administrators, when faced with budget shortfalls, to suspend or reduce maintenance activities that have a lower performance risk in favor of performing activities that have a higher one. This will dampen the impact of budget fluctuations on highway maintenance operations by performing critical maintenance treatments at the expense of less critical. / text

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 268-278). Also available via the Internet.