While not accounting for a significant proportion of overall crashes, median crossover crashes in the state of Utah do account for a significant proportion of interstate fatalities. Due to the seriousness of median crossover crashes in the state of Utah, the need exists to evaluate the impact of median crossover crashes in the state, to identify locations where median crossover crashes may be occurring at particularly high rates, and to identify methods to help mitigate these crashes. Previous research has noted that median crossover crash rates appear to increase in the vicinity of interchanges. The purpose of this research, therefore, is to develop a strategy to mitigate median crossover crashes statewide and determine the role that the interchanges play in contributing to median crossover crashes. Fourteen years of crash data spanning the years 1992 through 2005 on Interstates 15, 70, 80, 84, and 215 were used to determine overall characteristics of median crossover crashes in Utah and determine the relationship between median crossover crashes and other types of crashes. Using a chi-square goodness of fit test, the distributions of median crossover crashes and all types of interstate crashes in the vicinity of interchanges were compared. Three-year median crossover crash rates spanning the years 2003 through 2005 for rural and urban areas were then used to identify which sections of Utah interstates are most prone to median crossover crashes. Finally, recommendations were made concerning appropriate median barrier installation for the 37 critical sections as identified by the three-year analysis.

The state of roadside ditch design and performance has become a topic of concern for the Virginia Department of Transportation. Erosion failures of roadside ditches have occurred frequently enough to indicate that it may be desirable to revise the current design practice. Through the Virginia Transportation Research Council, VDOT has sponsored this research to investigate the state of design practice for these structures and to explore revisions to the design process resulting in a more economical design. To investigate the erosion problems, various VDOT personnel at each of Virginia's nine Construction Districts were interviewed with the intent to gain an understanding of roadside ditch performance in each District. When possible, field visits were made to sites experiencing erosion failure and soil samples were collected for analysis. In addition, experiences and design procedures in neighboring states were reviewed, with the objective of determining if similar problems have been experienced, and if so, how they have been addressed. The survey of other states included nine states, and a site visit to the Mount Airy District of the North Carolina Department of Transportation. A study of the literature relating to the hydraulic performance of unlined and lined ditches was also performed, with the objective of researching available stability criteria used in ditch design and determining if suitable values of Manning's n are being used in Virginia design. The results of this study presented in this thesis represent the best recommended roadside ditch design practice based on current available research. Recommendations include revisions to the current relationship of soil type and maximum allowable velocity, revisions to the application of Manning's n for various lining conditions, and suggestions to improve the overall design and construction process based on surveyed VDOT experience, surrounding states and current research. Future research will be necessary to improve the scientific bases for these recommendations / Master of Science

As America's infrastructure ages, many of the nation's bridges approach the end of their service life. In order to develop a method for handling the rising number of deficient and functionally obsolete bridges, nondestructive tests and evaluations must be undertaken. Valuable information from these tests regarding the strength and condition of bridges will help in making decisions about their rehabilitation and replacement. Two adjoining open spandrel reinforced concrete arch bridges in downtown Appalachia, Virginia were selected for live load testing by Virginia Department of Transportation (VDOT). Both bridges have supported an increasing amount of extreme coal truck traffic throughout their service life and are essential to the efficient transport of coal in the region. Because of their age, having been built in 1929, and the amount of visible damage and repairs, VDOT was concerned about their remaining capacity and safe operation. The live load tests focused on global behavior characteristics such as service strain and deflection as well as local behavior of the arches surrounding significant repairs. It was found that the strain and deflection data collected during load testing displayed linear elastic behavior, indicating excess capacity beyond the test loads. Also, given the loading applied, the measured strains and deflections were small in magnitude, showing that the bridges are still acting as stiff structures and are in good condition. Data collected during these tests was compared to results from a finite element model of the bridges to determine the coal truck size which is represented by the live load test loading configurations. The model comparisons determined the test loads produced comparable deflections to those produced by the target coal truck load. Through this approach, a recommendation was given to VDOT regarding the satisfactory condition of the aging bridges to aid in the process of load rating and maintenance scheduling for the two bridges. / Master of Science

The trend to outsource the engineering functions in state departments of transportation (DOTs) to private consultants has increased in recent years. However, most DOTs do not have a strategic approach to the outsourcing of engineering functions or projects. This thesis addresses that gap by examining outsourcing decision-making in the Texas Department of Transportation (TxDOT) and developing a rationalized procedure. TxDOT, the largest state DOT in terms of annual construction program,expends about 65% of its engineering on consultants. Staff from 18 of TxDOTs 25 districts were interviewed for this research, and Strengths, Weaknesses, Opportunities, and Threats (SWOT) Analysis is used to identify improvements to the current decision-making processes. A framework is presented for systematic assessment of the outsourcing potential of engineering functions, which would enable TxDOT districts to determine what engineering work to contract out cost-effectively without sacrificing core competencies. / text

Major projects around the world have long been notorious for cost overruns and schedule delays. In response to the cost overruns, the U.S. Department of Transportation established a task force and took a range of steps to strengthen the stewardship, management, and oversight of major projects at the beginning of the 21st century. Through a classical test of hypotheses, this study first investigates the prevalence and magnitude of the cost overruns of the major infrastructure projects in the U.S. before and after the reform. The before and after comparison finds that the projects experiencing cost overrun have been reduced from 77% to 45% following the reform. Results revealed that the U.S. Department of Transportation has developed measurable outcomes but their success may be limited. To address the cost overruns, conversely, the U.K. adopted Kahneman’s Nobel Prize-winning theory to challenge biases in human judgment and mandated reference class forecasting for major projects at the beginning of the 21st century. Through before-and-after and with-and-without comparisons of major infrastructure projects, this empirical study then examines the practical relevance of reference class forecasting for infrastructure investments. A before-and-after comparison reveals that the average cost overrun declined from 50% to 5% following the introduction of reference class forecasting. A with-and-without comparison also demonstrates that the U.K. surpassed its targeted probability of completing projects within budget by 12% using reference class forecasting, whereas the U.S. underperformed by 23%. Thus, reference class forecasting has engendered notable improvements in estimation in the U.K. Although schedule delays not only result in significant financial implications to project sponsors but also lead to substantial social costs to the public, scant attention has been dedicated to schedule delays. Therefore, this study further investigates the frequency, magnitude, and characteristics of schedule delays occurring during the construction of major infrastructure projects built in the U.S. and the U.K. between 1999 and 2018. A multivariate regression analysis confirms that length of implementation phase and project type plays the most important role in project schedule performance. During extensive efforts were made to project controls in the U.S. and the U.K. over the last two decades, this study also finds, project performance has not improved at all from a schedule perspective. In order to address the issue, this study suggests reference class forecasting to develop more realistic and reliable schedule estimates. This empirical study demonstrates the benefits of supplementing or replacing the current forecasting method. The findings can be used to reduce substantial financial risks for the government as well as social and economic welfare losses for society.

The monetary quantification of inconveniences caused to the road users by ongoing construction activities is known as the Road Users Costs (RUCs). While the importance of RUCs is widely known, some highway agencies lack an appropriate methodology to compute RUCs. Thus, there is a need to develop a framework to compute RUCs that can be adopted quickly by highway agencies. This study reviewed existing literature and conducted a nationwide survey to identify and summarize the current practices of computing RUCs. It developed an enhanced framework and tool to compute RUCs that balances the effort required to calculate RUCs and the accuracy of the results. This enhanced framework accounts for the spatiotemporal variation of RUCs. The results of the study are expected to enable highway agencies to quickly and accurately compute RUCs to make better project management decisions, such as selecting the best contractor that minimizes the agency costs and RUCs.

No description available.

Property Management, one functional area within Right-of-Way offices in state transportation agencies, is responsible for managing the property acquired for highway projects. These activities are data and document intensive and efficiency for performing them would be improved through the implementation of an information management system. Because of the geospatial nature of many of these activities, geographic information systems (GIS) would increase the effectiveness of this system. A literature review and survey were conducted to understand the current state of practice for the use of GIS and information management systems in Property Management. There is no identified comprehensive system that covers all Property Management activities. An initial step in developing a geospatially-enabled enterprise-level information management system, a logical model was developed. This included developing the business process diagram, business process models, and use case models based on the principles of systems engineering using the Computer Aided Software (CASE) Enterprise Architecture. Activities that would benefit from a geospatial component have been identified and included in the models. The developed models have been validated by working with PennDOT staff. The resulting model serves as a standard template for state transportation agencies and helps conceptualize the advantages of integration and interaction with other systems, and geospatial enablement prior to investment in an information management system. / Master of Science

Horse and buggy transportation is spreading as rapidly as its Amish and Old Order Mennonite users are, as are buggy crashes with motor vehicles. This study examines the primary causes of 76 reported horse and buggy crashes in Pennsylvania in 2006. The main crash types identified include a motorist rear-ending a forward-moving buggy, motorist failing to pass a buggy, buggy struck while crossing an intersection, and buggy struck while making a left turn. While causative factors varied for each crash type, major factors include the motorist or buggy driver incorrectly comprehending speed differentials, the motorist acting carelessly around the buggy, and miscommunication between the motorist and buggy driver. Within these crash types, buggy conspicuity was neither a major issue nor a possible cause in most.

As a result of the changing needs of society since the early 20th century, approaches to transportation planning have been continually shifting from highway-focused to multimodal, an approach which takes multiple modes of transportation into consideration. This evolution has been reflected in federal transportation legislation and continues to have many implications for transportation agencies, especially state departments of transportation (DOTs). The objective of this thesis is to analyze what state DOTs have done in order to adapt to the shift. More specifically, the project focuses on the organizational and funding structures of state DOTs. First, an organizational structure analysis of all 50 state DOTs was carried out. This analysis looked at how state DOTs incorporate multiple modes of transportation into their organizational structure. Secondly, the results of a statewide multimodal planning survey, to which 35 states responded, were analyzed. The survey gauged to what extent the representative from a given state DOT thought that their agency was conducting multimodal transportation planning. It also analyzed state DOT modal responsibilities, funding options, and characteristics that influence multimodal transportation planning. Lastly, case studies were carried out for six state transportation agencies: Florida DOT, North Carolina DOT, Oregon DOT, Virginia's Transportation Secretariat, Maryland DOT, and Massachusetts DOT. These case studies focused on organizational structure, funding, and multimodal efforts. Findings from the three different aspects of this thesis support the notion that highway is still the dominant mode in statewide transportation planning in most state DOTs. However, this research also supports the idea that this situation is changing, though more rapidly in some states than in others. Though it is not evident that one type of organizational structure is better than another, states have used the reorganization of these structures as a method for adapting to multimodal transportation planning. Overall, state DOTs tend to incorporate multiple modes of transportation into their organizational structure through multimodal divisions, separate modal divisions, or a combination of both. In addition to the organizational structures, some states have also restructured their funding mechanisms in order to make funds more flexible across all modes of transportation so that they may be able to better accommodate multimodal transportation planning. Those state DOTs with transportation trust funds and separate modal programs have generally shown more initiative in embracing a more multimodal approach to transportation planning. Besides organizational and funding structures, leadership, organizational culture, and institutional issues have been recognized as factors that influence the extent of multimodal planning.