Title from PDF of title page (University of Missouri--Columbia, viewed on Feb. 12, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Thesis advisor: Dr. Praveen K. Edara. Includes bibliographical references.

Thesis (Ph. D.)--University of Missouri-Columbia, 2008. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on June 8, 2009) Vita. Includes bibliographical references.

Thesis (M.S.)--University of Missouri-Columbia, 2005. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (July 11, 2006) Includes bibliographical references.

In recent years, there has been a considerable increase in the amount of construction work on the U.S. national highways. Most of the work undertaken is the reconstruction and rehabilitation of the existing transportation networks. Work zones in the United States are likely to increase in number, duration and length due to emphasis on repair and highway reconstruction as a significant portion of all federal-aid highway funds are now geared toward highway rehabilitation. The challenge of mobility is particularly acute in work zone areas as road repair and construction intensifies traffic issues and concentrates them in specific locations and at specific times. Due to the capacity drop, which is the result of lane closure in work zone area, congestion will occur with a high traffic demand. The congestion increases number and severity of traffic conflicts which raise the potential for accidents; furthermore traffic operational properties of roadway in work zone area become worse. Intelligent Transportation System (ITS) technologies have been developed and are being deployed to improve the safety and mobility of traffic in and around work zones. In several states in the US, the use of Dynamic Merge Controls also known as Dynamic Lane Merge (DLM) system has been initiated to enhance traffic safety and to improve traffic flow in work zone areas. The DLM usually takes two forms; dynamic iii early merge and dynamic late merge. The use of variable speed limit (VSL) systems at work zones is also one of those measures. VSL systems improve safety by helping the driver in determining the maximum speed that drivers should travel. Besides adding improvement to safety, they are also expected to improve mobility at the work zones. The main goal of this study is to evaluate the safety and operational effectiveness of the dynamic merge systems i.e. the dynamic early lane merge and dynamic late lane merge, in the presence of VSL system. More specifically, the VISSIM model is utilized to simulate a twoto-one lane configuration when one out of the two lanes in the work zone is closed for traffic. Six different scenarios were adopted to assess the effectiveness of these scenarios under different traffic demand volumes and different drivers‟ compliance rates to the messages displayed by the systems. These scenarios are;  Work Zone without VSL and without SDLMS or the current Motorist Awareness System (MAS)  Work Zone with VSL and without SDLMS  Work Zone with VSL and Early SDLMS  Work Zone with VSL and Late SDLMS  Work Zone with early SDLMS and without VSL  Work Zone with late SDLMS and without VSL iv An already calibrated and validated VISSIM model for Simplified Dynamic Lane Merge System (SDLMS) in accordance with the real life work zone was modified with a VSL through Vehicle Actuated Programming (VAP) code. Three different logics were coded each for VSL alone, early SDLMS+VSL and late SDLMS+VSL. All these logics were fine tuned with several test runs before finalizing it for the final simulation. It is found through the simulation of above mentioned scenarios that for low and medium volume levels (V0500, V1000 and V1500), there is no significant difference between the Maintenance of Traffic (MOT) plans for mean throughputs. However, for higher volume levels (V2000 and V2500), late SDLMS with and without VSL produced higher mean throughputs for all compliance rates and truck percentages except when the demand volume was 2,500 vph and compliance of 60%, where it produces the significantly lower mean throughputs. In terms of travel time through the work zone, results indicated that there is no significant difference between MOT types for demand levels of V0500 and V1000 when compliance is 40% or less but for compliance of 60% and more, only demand volume level that is not significantly different from other MOT types is V0500. This study revealed that VSL increases travel time through the work zone. This might be due to non-compliant vehicles that follow the compliant vehicle v ahead unless they find a sufficient gap in adjacent lane to pass the compliant vehicle. It is also found out that VSL makes the system safer at higher volumes (2,000 vph and 2,500 vph). This was observed through safety surrogate measures selected for this study. Another outcome of this study is that the addition of VSL to the dynamic merge systems helps in improving the overall safety of the system by lowering speed variances and deceleration means of the vehicles travelling through the work zone. The passage of traffic through the work zone is made safer when a speed control is integrated to a dynamic merge system. It can be inferred from the simulation results that integrated SDLMS and VSL systems have better performance in terms of traffic mobility and safety than existing individual controls and also show that the integrated SDLMS and VSL system has more potential than each individual systems.

Work zones are visually and physically complex environments, requiring that drivers maintain control of their vehicle and comprehend atypical and often discontinuous traffic control devices to safely navigate appropriate paths. Freeway diverges represent particularly difficult work zones areas. This thesis investigates current methods of delineating diverges in freeway work zones to determine important characteristics of these methods for future research. A virtual environment was constructed with two ramp geometries: a freeway continuing straight and one curving left. Still images of work zones on these geometries were created using drums spaced 10 ft apart, drums spaced 40 ft apart, drums spaced 40 ± 2 ft apart, and portable concrete barriers. These alternatives were used to construct temporary ramps that were either open or closed. 39 participants were asked to identify whether the ramp was open or closed and their responses were recorded to evaluate the performance of each alternative. Results indicate the importance of the Gestalt principles of closure, proximity, and continuity in perception of temporary exit ramps in work zones. These results will be used to guide future research into methods of delineating diverges in freeway work zones.

Thesis (M.S.C.E.)--University of Massachusetts Amherst, 2008. / Includes bibliographical references (p. 71-72).

Construction zones are traffic way areas where construction, maintenance or utility work is identified by warning signs, signals and indicators, including those on transport devices that mark the beginning and end of construction zones. Construction zones are among the most dangerous work areas, with workers facing workplace safety challenges that often lead to catastrophic injuries or fatalities. In addition, daily commuters are also impacted by construction zone detours that affect their safety and daily commute time. These problems represent major challenges to construction planners as they are required to plan vehicle routes around construction zones in such a way that maximizes the safety of construction workers and reduces the impact on daily commuters. This research aims at developing a framework for optimizing the planning of construction detours. The main objectives of the research are to first identify all the decision variables that affect the planning of construction detours and secondly, implement a model based on shortest path formulation to identify the optimal alternatives for construction detours. The ultimate goal of this research is to offer construction planners with the essential guidelines to improve construction safety and reduce construction zone hazards as well as a robust tool for selecting and optimizing construction zone detours.

CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / A velocidade de concepÃÃo e de execuÃÃo das infraestruturas tem aumentado devido à utilizaÃÃo de softwares e equipamentos eficientes, o que tem exigido um melhor desempenho de cada etapa. No entanto, apesar dos custos envolvidos com equipamentos serem os itens de maior peso na construÃÃo rodoviÃria, poucos sÃo os sistemas existentes de apoio à decisÃo para a seleÃÃo das frotas. Propostas de seleÃÃo de frotas tÃm sido elaboradas por pesquisadores no Brasil e no mundo, porÃm a maioria consideram apenas caminhÃes e escavadeiras/carregadeiras ou scrapers. Este trabalho tem como objetivo desenvolver um sistema de apoio à decisÃo na seleÃÃo de motoniveladoras para a execuÃÃo de obras de terraplenagem e de pavimentaÃÃo, denominado SADPATROL. Inicialmente, foi feita uma anÃlise da evoluÃÃo tecnolÃgica do equipamento motoniveladora visando verificar a influÃncia destas melhorias sobre o aumento da produtividade. Foram analisadas as equaÃÃes existentes na literatura para o cÃlculo de produtividade e apÃs verificada a representatividade da equaÃÃo utilizada no paÃs esta foi escolhida para compor o SADPATROL, com as devidas alteraÃÃes em suas variÃveis. AtravÃs da anÃlise de cada variÃvel da equaÃÃo foi possÃvel identificar o quanto as mesmas influenciavam no resultado da produÃÃo desta forma, foram implementadas melhorias, como a inserÃÃo de valores padrÃes para as variÃveis do sistema, permitindo a obtenÃÃo de resultados mais precisos, caso o usuÃrio nÃo possua dados medidos em campo. O SADPATROL possui cadastrado em seu banco de dados 46 tipos de motoniveladoras, dos mais variados modelos e tamanhos, de 12 fabricantes distintos. à possibilitado ao usuÃrio calcular a frota com equipamentos prÃprios e verificar se esta atende ao prazo da obra. Caso o prazo nÃo seja atendido pela frota prÃpria ou o usuÃrio nÃo possua equipamentos, o sistema executa as informaÃÃes da obra para todos os equipamentos do banco de dados e fornece a soluÃÃo com as 46 opÃÃes organizadas em frotas, em ordem crescente de quantidade de equipamento. à possibilitado ainda selecionar os equipamentos nos quais se possui informaÃÃo de custo horÃrio, para assim obter a frota de menor custo. Toda a multiplicidade de informaÃÃes necessÃrias à seleÃÃo de motoniveladoras, e suas inter-relaÃÃes e dependÃncias, foram organizadas de forma sistÃmica no software SADPATROL, diminuindo assim o empirismo e a dependÃncia da experiÃncia humana na seleÃÃo de frotas. A presente pesquisa pode ainda contribuir para auxiliar a elaboraÃÃo de normas tÃcnicas e para a disseminaÃÃo do conhecimento sobre o referido equipamento. / The demands on speed and efficiency of infrastructure design and construction has increased due to the use of software and more productive equipment, which has required better performance of equipment planners at each step. However, even considering that the costs associated with equipment are one of the items with the greatest weight in road construction, there are few computerized systems for fleet selection decision support. Fleet selection systems have been developed by researchers in Brazil and worldwide, but most of them consider only trucks and excavators/loaders or scrapers. This research aims at developing a decision support system for the selection of motor graders for construction activities involving earthmoving and paving works named SADPATROL. Initially, an analysis of the motor grader technological evolution was performed in order to evaluate the influence of the improvements on productivity gains. The equations presented in the literature were studied for productivity calculation and, after verifying the suitability of the equation, the equation was incorporated in the SADPATROL system with the necessary changes in its variables. Through the analysis of the variables in the equation, it was possible to identify how they influenced the productivity. Through this analysis, improvements were implemented. These improvements consisted of the inclusion of standard values for the system variables, allowing the achievement of more accurate results if the user has no data for productivity measured in the field. The SADPATROL system has 46 types of motor graders included in its database, from many different models and sizes and from 12 different manufacturers. The user is able to plan the fleet with its own equipment and verify if it satisfies the construction project deadline. If the deadline cannot be satisfied using the available fleet or the user has no equipment, the system performs the construction planning using all database equipment and provides the optimal solution with 46 options organized into fleets in increasing order according to the amount of equipment needed. It is also possible for the user to select the equipment using time cost information and, thus, achieve the lowest cost fleet. The significant amount of information necessary for motor graders selection and its inter-relationships and dependencies were organized in a systematic way in the SADPATROL system, reducing, the empiricism and the dependence on human expertise in selecting fleets. This research may also help in assisting in the development of technical standards and expanding the dissemination of knowledge about such equipment.

The purpose of the following report is to account for and summarize the authority and tasks that municipalities, authorities and contractors have in the implementation of temporary traffic diversions. In addition to this, the cooperation between all actors has also been investigated with the aim of finding out what types of routines and potential tools are used in connection with the work. The implementation of the report is based on a qualitative study, for which relevant people with different tasks have been interviewed or answered questionnaires. Furthermore, governing documents for relevant parties have been studied with the intention of describing the requirements that apply to work adjacent to or on the road. The results have subsequently been compiled in an account of the work parties' tasks, views and suggestions for improvement. In this it appears that the road maintenance authorities have an examinative responsibility and has the authority to approve the work carried out on its behalf. For and in particular all road works, of which the diversion is a part, traffic device plans must also be drawn up and describe solutions for traffic-related problems. These are the tasks of the executing contractor to draft with regard to the requirements of the road maintenance authority. It also appears that the majority of the interviewees consider the cooperation to be satisfactory, but state how interpretation of the governing documents can result in conflicts between the parties. In addition, significant differences for the systems used in the coordination can be noted for each municipality and authority.

No description available.