William Rasdorf

The purpose of this research is to add new insights regarding the benefits and drawbacks of using intersections with three-phase traffic signals compared to other intersection designs and to develop a technical guideline to help designers and policymakers in transportation understand when and where to use three-phase designs. At four-phase conventional intersections where traffic demand is near or above capacity, innovative intersections may perform better. New designs with two-phase traffic signals such as reduced conflict intersections (RCI, also called RCUT and superstreet) result in shorter travel times, fewer crashes, and better pedestrian service in North Carolina (NC). However, retrofits to designs with two-phase signals may be impactful and unpopular. Higher minor street demand, lack of precedent, and complaints (from neighbors, business owners, politicians, media, etc.) are among the possible obstacles for constructing two-phase designs in many locations. In other words, while two-phase intersections perform very well at many intersections, designers might not be able to select those designs for some projects. On the other hand, intersections with three-phase signals might provide some of the two-phase design advantages while also providing more direct movements and alleviating some public concerns. This study seeks to answer the following questions: (1) At what locations are three-phase designs most well suited? (2) How much do they cost, especially compared with other intersections like RCIs? (3) What kind of traffic control devices (pavement markings, traffic signs, and traffic signals) are needed? (4) What movement restrictions could cause motorist confusion and violations? (5) How could we minimize those violations? (6) What are the considerations needed for pedestrian and bicyclist safety? (7) What kind of geometric and right-of-way (ROW) limitations are faced during construction? (8) What movements are less impactful for redirecting in different cases? (9) What designs would be most readily accepted by the public? Current literature on innovative intersections with three-phase signals is limited. Excluding offset, partial continuous-flow intersections (CFIs), and quadrant intersections, (three common three-phase designs in NC) little information is available on the performance of other three-phase intersections. Reviewing the Crash Modification Factors (CMF) Clearinghouse reveals that only a few studies have estimated CMFs for converting four-phase conventional intersections to three-phase intersections. These studies focused on partial CFIs and partial median U-turn intersections (MUTs). Other possible three-phase designs should also be evaluated to increase the confidence level in selecting the most appropriate design. A recent presentation by NCDOT????????s Dr. Joseph Hummer introduced ten three-phase intersections as possible candidates for future projects. Based on initial evaluations, the ten three-phase designs could show potential in improving existing intersections. The research team also proposes another new three-phase design which could be considered as a promising design. The proposed three-phase intersection redirects two left-turn and one through movements. It is expected to experience higher capacity for the proposed design compared to conventional intersection due to better signal progression and a lower volume to capacity (v/c) ratio. Also, the proposed design has 19 conflict points. Only two of the existing three-phase designs (reverse RCI and offset intersections) have fewer conflict points compared to the proposed design. This proposed study focuses on the following three-phase designs: partial MUTs, partial CFIs, reverse RCIs, thru- cuts, offset, quadrant, CFI/MUT combo, redirect one minor leg, redirect minor lefts, seven-phase signal, and redirect two lefts and a through intersection (see Figure 1 in the body of the proposal). Also, the research team will consider other new designs, especially where another proposed design might perf

The purpose of this research is to assess NCDOT traffic signal maintenance procedures and signal replacement cycle to benchmark their costs so that signal performance is maintained or enhanced and to develop a model for LED powered signal life span. This study answers the question ????????????????what is the threshold at which an acceptable working LED traffic signal is in need of replacement???????????????? This study will explore whether or not a systematic signal replacement strategy could be developed and used by any division within NC to enhance performance, reduce waste, reduce cost, and be realistically and efficiently implemented.

Alternative Intersection and Interchange (AII) designs are those which provide an innovative approach to the geometric or control features which may improve operations and/or safety for different road users. In 2010, the U.S. Federal Highway Administration (FHWA) published the first edition of ????????????????Alternative Intersection and Interchange Informational Report??????????????? (AIIR), which provided information on six alternative treatments including displaced left-turn (DLT) intersections, restricted crossing U-turn (RCUT) intersections, median U-turn (MUT) intersections, quadrant roadway (QR) intersections, double crossover diamond (DCD) interchanges, and DLT interchanges. For each treatment, AIIR presented detailed information in a standardized format, including salient geometric design features, operational and safety issues, access management, costs, construction sequencing, environmental benefits, and applicability. The AIIR first edition has been employed by various agencies as a valuable resource for planning and designing AIIs, there are still unconventional design concepts that have not been fully explored and some of the current ones could use updates. During the past decade, there have been an increasing number of AIIs installed in the United States, and more new AII designs that are not documented in AIIR first edition have emerged since 2010, such as Reverse RCUTs, Partial Median U-turns, and Grade-Separated Alternative Intersections, etc. These new AII designs may involve different traffic organization patterns, which may introduce confusion and create safety hazards for drivers. NCDOT is a national leader in AII implementation, which provides safe, efficient, and cost-effective travel solutions for North Carolina drivers. Therefore, the primary objective of this research is to start the process of compiling the AIIR Second Edition. Specifically, this research will provide a state-of-the-practice literature review and expert interviews on AII designs, draft an annotated outline for the AIIR second edition, and develop an updated set of simulation models to assess the performance of various AII designs. Finally, this research will provide practical recommendations for planners and engineers to select site-specific AII designs during project processes.

The purpose of this research is to assist the NCDOT Traffic Management Unit (TMU) and the Value Management Office (VMO) in assessing issues regarding the construction of Diverse, Modern, and Unconventional Intersections and Interchanges (DMUII). Assessing the constructability of these emerging DMUII is a new area of study that has not yet been previously explored. Therefore, this research will identify factors affecting construction projects prior to construction and develop a schedule and cost payout model (based on prior NCDOT projects) that identifies problems related to expenditure, schedule, and obstruction of traffic during construction.

The North Carolina State Institute, in its role as subcontractor to East Carolina University, will perform a total of $109,639 in contracted work from the period of August 2019 to July 2021. 1. Task 1. Kickoff Meeting. NC State will assist with the identification and scope of the research project. In addition, NC State will assist in the presentation of the data collection plan, methodologies for data analysis, and final products, as directed by ECU. 2. Task 2. Develop Literature Review on Best Practices. For this task, NC State will work collaboratively with ECU in the development of the literature review concerning best practices for conducting the constructability review process. Where appropriate, NC State will provide the relevant expertise and guidance. 3. Task 3. Schedule Stakeholder Meetings and Attend Constructability Review Meetings. will work collaboratively with ECU to schedule phone interviews with relevant stakeholders, focusing on those who have participated in previous constructability review meetings. In addition, NC State will lead the development of a comprehensive database of concerns raised by various project stakeholders (e.g., project owner, design engineers, general contractors, etc.) 4. Task 4. Refine Review Process and Establish Metrics. For this task, NC State will assist ECU in the development of constructability metrics and, where appropriate, establish new metrics for review. NC State will assist in the presentation of findings and metric recommendations to NCDOT. 5. Task 5. Develop Tracking Methods/Benefits Assessment Methodology and Tool. NC State will assist in the development of the tool methodology and action plan; NC State will lead in the database development. Finally, NC State will assist in the development of the draft constructability review tool which will be provided to NCDOT Value Management Office staff. 6. Task 6. Development of Action Plan and Spreadsheet Tool. NC State will assist in the refinement and development of the final constructability review tool to NCDOT staff. In addition, NC State will assist ECU in providing a final action plan report (with recommendations) to NCDOT.

Recent advances in small unmanned aerial systems (UASs) and sensing technologies have enabled relatively low cost and effective surveying methods for preconstruction, construction, and slope sites. However, the commercial software that accompanies these technologies produces inconsistent and unreliable survey results and there are no guidelines for ensuring the quality of the data. Without proper guidelines and specifications, repeated surveying at a designated area over time (e.g., construction site with periodic data collection) is not ideal.

Individual students applied for the DDETFP Fellowship. The selected student, their faculty advisor or campus program manager, and the institution 6 (????????????????Recipient???????????????) will be responsible for completing and submitting all required paperwork to execute the fellowship. Funding will be sent to the Recipient on behalf of the Student Designee. The Recipient will be responsible for allocating funds to the student as outlined in the Budget of this Agreement. The Recipient will also be responsible for submitting all required reports to FHWA.

The Powell Bill Unit of the NCDOT annually distributes a fixed appropriation from the State Highway Fund to qualified North Carolina municipalities to maintain municipal streets within their corporate limits. The eligible activities covered by the funds include construction, planning, and maintenance on streets, sidewalks, bikeways, and greenways such as resurfacing, patching, widening, storm drainage, curb and gutter, and patching. It can also be used for municipal street bond debt service and traffic control such as traffic control devices, traffic signs, speed bumps, traffic paint, and traffic cones.

The purpose of this research is to assess alternate NCDOT roadway sign replacement strategies and to benchmark their costs so that sign performance is maintained or enhanced while lowering costs. This study answers the question ????????????????is there an implementable lower cost sign replacement strategy that meets or exceeds current performance levels???????????????? This study will explore whether or not this strategy could consist of a systematic sign replacement strategy that can be used by any division within North Carolina.

Asset management is a relatively new concept in geotechnical engineering. In general, the nature of earth structures within the realm of highway engineering renders the concept of asset management a valuable tool for operation efficiency and cost control. Asset management includes a database of assets, tools to manage the database, asset condition assessment models, and strategies for assessment, mitigation, rehabilitation, and replacement. At present, there is no systematic tool to provide electronic documentation and analysis of earth structures including the retaining wall inventory maintained by the North Carolina Department of Transportation (NCDOT). The objective of this research is to design and develop a database archival and retrieval system for electronic documentation, management, qualitative analysis, and display of retaining walls, especially critical walls such as those adjacent to bridges. Such structures include MSE, soil-nail, tie-back, gravity, cantilever, and pile panel walls. The prototype database to be created will include wall location, geometry, internal configuration, local geology, and external signs of stress such as tilt and cracking. The development of rating criteria models that are specific to particular wall types will also be explored in consultation with NCDOT. The development of a systematic means for cataloging and condition assessment of highway retaining structures will represent a major contribution to the ability to establish effective and sustainable maintenance and replacement priorities. The primary project product is referred to herein as a database and includes a definition of all data tables and the attributes they contain. The final report will provide these definitions as well as sample data for 12 existing retaining walls populating all tables. Data collection procedures will include both wall spatial as well as wall attribute (characteristics) data. The spatial data will be organized in such a way as to be able to link to existing NCDOT systems. The proposed database (of key parameters defining the various types of retaining walls within the state) is intended to assist NCDOT engineers and contractors in evaluating the need for maintenance and replacement as well as capture often-lost assets for effective master planning, engineering, design, maintenance, and management of highway retaining structures.

The purpose of this proposal is to provide NCDOT with a design of a model to accurately portray construction costs of mega projects on a monthly basis. The model will track and document in-place cost and predict future costs based on NCDOT??A???a?sA???a?zA?s historical cost records for mega projects. It will also enable NCDOT to simulate changes in scheduling and depict the impact of those changes on payout costs. Finally it will enable NCDOT to identify projects that are deviating from their optimal cost payout curve pattern, pinpoint the factors causing that deviation, and allow NCDOT to be more proactive in making more informed cash flow management decisions. Key factors that influence the predictability of Preliminary Engineering (PE), Right-of-Way (ROW), and Construction expenditures for mega projects will be studied. A series of interviews will be conducted in the form of focus groups to help identify the key influencing factors that affect expenditure predictability for these categories. From these interviews a set of key variables will be identified that most significantly affect cost payouts. This phase will focus on the question of what factors will have the greatest influence in predicting project timeliness and cost. A qualitative assessment of the factors will be made and an assessment of their probability of impact will be determined for PE, ROW, and construction. The model design will include model objectives, data requirements and sources, approach/methodology, software platform, development and testing timeline, and expected performance parameters.

Previous research has not investigated how drivers use roadway signage for destination identification when simultaneously performing navigation and/or hazard avoidance. Furthermore, it is not known how drivers prioritize or manage such tasks when subject to information processing capacity demands due to in-vehicle distractions, such as navigation aid use. Although several studies have been conducted on the affect of logo sign formats on driver behavior, the effectiveness of specific formats for supporting driver cognition when distracted or posed with safety-critical driving situations is not known. The first objective of the present study is to describe how drivers prioritize performance and safety goals in the presence or absence of in-vehicle distractions. As drivers make decisions from moment-to-moment, which are related to achieving a destination or maintaining safe vehicle control, we also seek to describe the pattern of driver visual attention to information sources in the environment that are related to concurrent driving goals, including logo and warning signs. The second and final objective is to determine the effect of logo sign configurations, including conventional six-panel and nine-panel, on the capability of drivers to comprehend sign information under normal conditions and in the presence of competing safety concerns and distraction. The study will make use of a high-fidelity driving simulator and realistic simulation scenarios. Drivers will be exposed to highway driving for extended periods in which they are required to use a navigation device for destination exit identification, negotiate a construction zone and roadway hazards, and use logo signs for selecting an exit. Drivers will also complete trials is which use of the navigation device (or in-vehicle distraction) is not required. Driver safety margin measures (time headway) will be collected to make inferences on goal management. Performance measures will be collected to assess the stability of speed and position control under distraction and when using signage. Visual behavior measures will be collected to assess levels of driver distraction due to navigation device use as well as the extent of focus on various roadway sign formats. Results are expected to provide insight into how drivers alter performance and safety goal structures when posed with in-vehicle distraction tasks, as well as how goal management and distraction translate to the use of roadway signs. Recommendations will be made to the NC DOT regarding optimal logo sign configuration for various driving circumstances. Such recommendations may impact actual NC DOT sign installations and, consequently, motorist use of signs on North Carolina Highways.

Logo signs are defined as guide signs that provide road users with business identification and directional information for services and for eligible attractions. Eligible service categories include gas, food, lodging, camping, and attractions. The number of businesses providing motorist services has grown at many interchanges on North Carolina freeways. At some interchanges, the number of qualifying businesses providing a certain service exceeds the maximum six panels per sign. In 2005, the North Carolina Department of Transportation (NCDOT) began experimenting with nine-panel signs at some of those locations. The NCDOT also uses mixed-use overflow signs at some of these locations. The recently published 2009 version of Manual on Uniform Traffic Control Devices (MUTCD) includes a significant logo sign policy change. The policy now allows for the use of overflow mixed-use logo signs. Section 2J.02.04 specifies that ?no service type shall appear on more than two signs?, which implies that two logo signs can contain the same type of service. It further specifies that ?where a service type is displayed on two signs, the signs for that service should follow one another in succession.? The 2003 version of MUTCD specified that ?no service type shall appear on more than one sign.? However, the new MUTCD maintains that ?no more than six logo sign panels shall be displayed on a single specific service sign.? Therefore, the new MUTCD still does not allow the use of nine-panel signs. No explanation or justification of the maximum use of six panels is given in the new MUTCD. A concern some express with more signs or signs with more information is added driver distraction. Driver distraction is defined as a diversion of attention away from activities critical for safe driving toward a competing activity (Lee et al., 2008). Multiple resource theory (MRT) describes this diversion in terms of competition for attention resources defined by four dimensions: processing stage, processing code, perceptual modalities, and visual channel (Horrey and Wickens, 2004). When the multiple demands compete for the same resource, performance of one or more of these tasks degrades. Cell phones, personal digital assistants (PDAs), and navigation devices are typical in-vehicle driver distractions. Traffic signs and billboards are typical on-road distractions. Driving functions such as glancing at the speedometer or back mirror are normally considered as a part of the driving task, not as driver distractions.

This research will study how to accurately estimate Preliminary Engineering (PE) costs for NCDOT highway projects. The goals of this research are to have a comprehensive study of the factors affecting NCDOT PE costs, to build a data query tool containing 10 years of NCDOT highway project characteristics and PE cost information, and to build tools to help NCDOT estimate PE costs accurately and efficiently. Due to funding source limitations, achieving these goals is critical for the NCDOT because PE costs are a large portion of overall project costs. 2007 NCDOT bridge project data shows that PE cost percentage of total project expenses (including ROW, construction, and PE) can vary over 15 percentage points from an average of about 20%. The lack of predictability in PE costs in the early stage means that budgets are often insufficient, which compromises the ability of the NCDOT to deliver its entire planned transportation program and erodes public confidence in the agency. The team will begin the research by developing a comprehensive list of factors affecting PE cost based on a literature review and NCDOT project data. Secondly, the team will conduct a statistical analysis of past NCDOT highway projects to identify the factors that have significant impacts on PE costs in the Planning and the Design Preconstruction areas. Data will be grouped by numerous factors including project type, project complexity, year, whether the PE was conducted in-house or by a consultant, etc. The average and range of variation for each group will be calculated. Thirdly, the team will build a data query tool containing 10 years of NCDOT highway project information to provide average and range on PE cost percentage of previous similar. Fourthly, the team will build a fuzzy neural network tool for PE cost ratio estimation. The inputs into the tool will be descriptions of project characteristics and the outputs of the tool will be estimated ratio of PE cost to total project cost. Finally, guidelines for NCDOT highway project PE cost estimation will be developed. The guidelines will include a checklist of important factors to be considered in PE cost estimation, a convenient estimation tool, a sensitivity analysis of those factors, and estimated ranges of variations of PE costs on previous similar NCDOT projects.

Horizontal curves are relatively dangerous features, with collision rates at least 1.5 times that of comparable tangent sections on average. There is a wide variety of traffic control devices available for horizontal curves, but the available guidance on applying devices to curves is quite general. Much discretion is left to field personnel, as the factors that matter in optimum device choices are too complex to distill into simple formulas or tables. The lack of guidance has led to great inconsistencies in the application of traffic control devices for horizontal curves throughout the state. Some of this inconsistency causes real problems in at least three ways, including confused and surprised motorists who often get in collisions, vulnerability to lawsuits, and wasted time and money.

NCDOT has adopted the Mechanistic-Empirical Pavement Design Guide. The implementation of this new pavement design process requires traffic data resources to provide the vehicle traffic load spectra needed for each pavement design. Load spectra derive from historical seasonal truck volume patterns and axle loading patterns and load spectra forecasts over the service life of a design. The expected results of the research will describe what detailed base year traffic data to collect (i.e., the data most sensitive to the MEPDG process), how and where to collect the traffic data in North Carolina, and how to develop forecasts.

With an investment of $1 million after five years of data collection, this summer the Work Zone Traffic Control Unit (WZTCU) requested that North Carolina State University (NCSU) develop a pavement markings research plan to analyze relationships between pavement marking retroreflectivity values and variables such as marking color, marking age, and pavement surface. The first step of this plan was to understand retroreflectivity performance over time. The plan then called for an application of this knowledge in a holistic asset management approach. This will enable pavement marking managers to focus their limited resources where they are most needed and avoid replacing materials with effective life still remaining. To date, North Carolina State University (NCSU) has met several times with NCDOT personnel and the data collection contractor, Precision Scan, LLC. Based on previous discussions with experts and based on a literature review of the existing state of research regarding pavement-marking performance, an initial assessment of the data was conducted and a research agenda has been established. It is now critical to continue this research for two reasons. First, the NCDOT has invested heavily in data collection and this data must be analyzed. Second, it is important to effectively evaluate the condition of the pavement markings throughout the state and determine if they will be in compliance with pending minimum retroreflectivity standards that the FWHA is proposing to publish. This research will evaluate the pavement marking performance characteristics of NC?s highways and propose asset management guidelines that will enable NC to effectively implement the new standards.

The Dwight D Eisenhower Transportation Fellowship Program has granted round trip travel expenses for Elizabeth Harris to attend the Transportation Research Board in Washington DC during the period of 9/01/07-9/01/08. The primary event will be attendance at the TRB Annual meeting. Estimated costs are $6500 including travel from Raleigh, NC to Washington DC, travel, lodging and conference registration. According to the grant letter, any remaining funds after TRB expenses may be applied to the student's tuition or living stipend.

The key project tasks include: (1) study design for field data collection; (2) conduct field data collection; (3) analyze data and develop typical duty cycles; and (4) demonstrate methods for estimating emissions for construction equipment. The project will feature the use of portable on-board instrumentation to measure second-by-second vehicle activity and emissions, applied to three primary vehicles. Preliminary candidate vehicles include backhoes, motor graders, and front-end loaders. The study design, including final selection of vehicles, will be done in consultation with the project advisory committee. The products of this work will include a database of measurements of real-world in-use activity patterns (duty cycles) and emissions, recommended duty cycles and emissions estimates to use as a basis for emission inventories, a case study of a construction vehicle fleet emission inventory, and a project final report.

The preliminary outcomes from SGER grant # CMS-0353175 have further highlighted the need for developing a common data set for multiple disasters based upon the input from all those in the chain of data collection and use. To determine such a common data set for a broad range of events related to disaster management, a wide variety of local participants must be consulted to truly establish both the relevant regional data needs and potential data collection opportunities. The proposed workshop, to be held in conjunction with North Carolina Emergency Management (NCEM) and the Institute of Disaster Studies (IDS), a statewide consortium of disaster response entities, would establish a paradigm for the creation of a local common data set. Methods of local data collection and usage clarified by the workshop participants would be applicable to Raleigh, North Carolina, as well as serve as a model that would be adaptable to the structure of other communities. The objectives for the workshop discussion are as follows: * Define information needs to support a disaster management system * Establish the quality, format and location of the data resources involved * Identify data gaps and possibilities to improve data collection and dissemination methods * Verify commonality in disaster information among multiple disaster types * Define objectives for pre-disaster organized disaster data gathering teams