Static speed limits are the norm across the world’s roadway networks. However, advances in technology and increased applications in intelligent transportation systems (ITS) provide a mechanism for upgrading traditional speed limits into an active traffic management system. More specifically, variable speed limits (VSLs) can be used in high crash severity locations and in real-time congestion and weather events to increase traffic safety and operations. Much of the available literature on VSLs focuses upon crash prediction algorithms for VSLs, simulations, and effectiveness of real-world VSL implementations. One noticeable gap in the existing literature is related to driver compliance under varied configurations of alerting drivers of the variable speeds. An additional gap in literature is related to existence of a conceptual framework for identifying optimal corridors for potential VSL implementation. Within this thesis drivers’ willingness to comply with VSLs was investigated via focus groups and static surveys during the experimental process. Connections are made between driver speed choice and type of speed limit condition including uniform speed vi limit (USL) versus VSL, overhead mount versus side mount, presence of an explanatory message, and the numerical speed limit value. An analysis of the survey results was completed to isolate critical factors in VSL compliance. Opinions and perspectives on VSLs are derived through the focus group sessions Lastly, a case study approach is presented in which a region is chosen, and implementation metrics are analyzed on the major roadway networks using a GIS platform to create a composite ranking system for potential optimal VSL corridors. The study aims to be used as a foundation to justify use of certain types of VSLs in addition to creating a conceptual framework for VSL implementation zone identification.

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.

Posting advisory speed signs at sharp horizontal curve sites is a practice well established in the United States. The purpose of these signs is to provide the driving public with a safe speed to negotiate such curves; however, the link between these signs and safety has not yet been clearly established. The first manuscript in this dissertation presents an effort to model safety as it relates to curve advisory speed signs. It proposes a statistical model relating crash frequency at 2-lane rural highways in Oregon to curve advisory speed signs and other influential factors. The Advisory Speed Crash Factor (ASCF) emerges as a sub-model that characterizes the safety effect of advisory speed signs. Results indicate that safety may be compromised if the advisory speed is either excessively prohibitive or excessively permissive. The second manuscript extends the use of the proposed ASCF to develop the OSU posting method, a new procedure that procures the "optimal" advisory speed derived from the ASCF. A field validation analysis, also presented in this manuscript, verified the meaningfulness of the proposed ASCF sub-model. The third manuscript outlines another methodology, named 'the Hybrid OSU Posting Method' in an effort to mitigate the well documented variability associated with using the Ball Bank Indicator (BBI). This method determines the advisory speed using the BBI in combination with the ASCF. Though benefits in safety performance and consistency resulted from using the Hybrid OSU method, this method is still outperformed by the computational OSU method. / Graduation date: 2012 / Access restricted to the OSU Community at author's request from May 25, 2012 - May 25, 2013

Variable Speed Limits (VSL) are often used to improve traffic conditions on congested motorways. VSL can be implemented as mandatory or advisory. The objective of the thesis isto study in detail the effectiveness of VSL. The focus is on both, design parameters and conditions under which VSL are most effective. The MCS system on the E4 motorway inStockholm is used as a case study. The evaluation was conducted using empirical methods (including aggregate data from microwave sensors and other sources, and disaggregate data from a mobile study), and microscopic traffic simulation. The empirical analysis is based on before and after VSL data, including evaluation of individual measures of performance, and multivariate analysis in the form of the fundamental diagram, and speed-density relationships. The results from the empirical study are mixed with an indication that driver behavior has a strong impact on the effectiveness of the system. The microscopic traffic simulation analysis included the development of a platform for testing VSL and more generally motorway control strategies. The simulation platform was calibrated and validated with the empirical data and includes in addition to VSL, and Automatic Incident Detection (AID) system, the ALINEA ramp metering algorithm. The test-platform allows the testing of different control strategies and various combinations of control strategies, under different scenarios and in a controlled environment. The results from the simulation study indicate that driver compliance is an important factor and VSL performance quickly deteriorates as compliance rate drops. Hence, VSL should be implemented as mandatory instead of advisory. In addition, mandatory VSL can be effective both, under incident and moderately congested conditions. A combined VSL and ramp metering strategy can be most effective in reducing travel time, improving traffic conditions on the motorway. Furthermore, the results indicate that such a strategy also has the least impact on the flows entering the motorway from the ramps. / QC20100630

Submitted by Ana Beatriz Guimarães Passos (ana.passos@gvmail.br) on 2017-06-07T12:58:01Z No. of bitstreams: 1 PASSOS, 2017, Limites de velocidade nas vias Marginais.pdf: 2863001 bytes, checksum: 19654c376b01490c16c45107cefccc47 (MD5) / Approved for entry into archive by Suzinei Teles Garcia Garcia (suzinei.garcia@fgv.br) on 2017-06-07T13:07:49Z (GMT) No. of bitstreams: 1 PASSOS, 2017, Limites de velocidade nas vias Marginais.pdf: 2863001 bytes, checksum: 19654c376b01490c16c45107cefccc47 (MD5) / Made available in DSpace on 2017-06-07T17:18:31Z (GMT). No. of bitstreams: 1 PASSOS, 2017, Limites de velocidade nas vias Marginais.pdf: 2863001 bytes, checksum: 19654c376b01490c16c45107cefccc47 (MD5) Previous issue date: 2017-05-10 / Speed is an important element in our culture, often associated with positive values such as productivity and efficiency. However, when applied to traffic, it is one of the main risk factors either for the occurrence or even the severity of accidents. For this reason, the management of speed limits has gained more and more relevance not only at the global debate on road safety, but also in the scope of the international agendas dedicated to the promotion of development in general. Therefore, with this reality in mind, the present dissertation studies the regulation of the speed limits in 'Marginal Pinheiros' and 'Marginal Tietê', two important avenues of São Paulo, the most populated city of Brazil. To achieve this goal, it examines the period between July of 2015, when the Administration of former Mayor Fernando Haddad (2013-2016) reduced the speed limits, and February of 2017, second month since the Administration of Mayor João Doria (2017- ) partially restored to previous levels. The main objective of this investigation is to carry out a case study that seeks to articulate the regulation in reference with the use of legal instruments by specific actors that pursued the repeal of both the increase or the decrease of speed limits. In this last respect, the study considers three main subjects, that are: (a) the lawsuits filed by the Bar Association of São Paulo (Ordem dos Advogados do Brasil, Seção de São Paulo) and the Association of Urban Bikers of São Paulo (Associação dos Ciclistas Urbanos de São Paulo), both against the Municipality of São Paulo; (b) the legislative project presented by the city councilman Eduardo Tuma (PSDB); and finally (c) the government programs presented by candidates who disputed the city elections of 2016 and 2012. This research intends to contribute to the Law and Development literature by offering a study on how legal instruments can be used to implement and also to strengthen or to repeal public policies. / A velocidade constitui elemento de destaque em nossa cultura, muitas vezes associada a valores positivos como produtividade e eficiência. Todavia, quando aplicada ao trânsito, representa um dos principais fatores de risco para a ocorrência e para a gravidade de acidentes. Por esse motivo, a gestão dos limites de velocidade tem ganhado cada vez mais espaço não só no debate mundial sobre segurança viária, mas também nas agendas internacionais dedicadas à promoção do desenvolvimento de um modo geral. Diante deste cenário, a presente dissertação volta-se ao estudo da regulação dos limites de velocidade nas Marginais Pinheiros e Tietê, importantes avenidas da cidade de São Paulo. Para tanto, examina o período de julho de 2015, momento em que a Administração do ex-prefeito Fernando Haddad (2013-2016) reduziu os limites de velocidade em tais vias, até fevereiro de 2017, segundo mês desde que a Gestão do prefeito João Doria (2017- ) estabeleceu a sua elevação parcial aos patamares vigentes anteriormente. O trabalho tem como objetivo geral a realização de um estudo de caso que procura articular, de um lado, a regulação em referência, e, de outro, o uso de instrumentos jurídicos por determinados atores no intuito de questioná-la. Considera, sobre este último aspecto, três enfoques principais: (a) as ações civis públicas ajuizadas pela Ordem dos Advogados do Brasil (Seção de São Paulo) e pela Associação dos Ciclistas Urbanos de São Paulo, ambas em face da Municipalidade de São Paulo; (b) o Projeto de Decreto Legislativo apresentado pelo vereador Eduardo Tuma (PSDB); e (c) os programas de governo dos candidatos que disputaram a Prefeitura da capital paulista nos anos de 2016 e de 2012. A partir desta pesquisa, pretende-se contribuir com a literatura do Direito e Desenvolvimento, oferecendo-se um estudo a respeito do modo pelo qual os instrumentos jurídicos podem atuar na implementação, no fortalecimento ou na paralisação de uma política pública.

This diploma thesis deals with the study of the new development of the current development area of the town of Kroměříž in its northeastern part behind the psychiatric hospital between the streets Lutopecká and Havlíčková. This territory connects the local part of Terezov and Barbořina. The aim of the study was to propose new housing for more than 1,200 inhabitants in a currently unbuilt area in accordance with a valid territorial plan. The solved territory is divided into three stages of construction. The northeastern part follows the existing housing development with two-storey apartment buildings. In the rest of the area there are designed individual houses and partly terraced houses. The area is complemented by a kindergarten, shops and a parking house. In accordance with the territorial plan there is also a park and a sports ground with a playground and a sports hall. The character of the territory is greatly influenced by some already existing engineering networks and their protection zones, the transfer of which is economically disadvantageous. Due to the marginal position of the solved territory, the study proposes the extension of the service by public transportation by another two places. The new transport link between streets Lutopecká and Havlíčková would cause a significant traffic movement to increase over the area, so the study envisages a calm traffic in the form of a maximum speed limitation of 30 km/h and the communication system consists of two-way and one-way communications. Transportation is provided by the garages belonging to family houses supported with parking along the roads. In the apartment part, parking is possible in the outdoor parking lots and to supplement the necessary capacity, the study also proposes a parking house.

Safety and congestion are ever present and increasingly severe transportation problems in urban areas throughout the nation and world. These phenomena can have wide-ranging consequences relating to safety, the economy, and the environment. Adverse weather conditions represent another significant challenge to safety and mobility on highways. Oregon is not immune from either of these global issues. Oregon Route (OR) 217, to the southwest of the downtown Portland, is one of the worst freeways for congestion in the state and is also subject to the Pacific Northwest's frequently inclement and unpredictable climate. High crash rates, severe recurrent bottlenecks and highly unreliable travel times continuously plague the corridor, making it a major headache for the thousands of commuters using it every day. In an effort to more effectively combat both congestion and adverse weather, transportation officials all over the world have been turning to increasingly technological strategies like Active Traffic Management (ATM). This can come in many forms, but among the most common are variable speed limit (VSL) systems which use real-time data to compute and display appropriate reduced speeds during congestion and/or adverse weather. After numerous studies and deliberations, Oregon Department of Transportation (ODOT) selected Oregon Route (OR) 217 as one of the first locations in the state to be implemented with an advisory VSL system, and that system began operation in the summer of 2014. This thesis seeks to evaluate the effectiveness of this VSL system through the first eight months of its operation through an in-depth and wide-ranging "before and after" analysis. Analysis of traffic flow and safety data for OR 217 from before the VSL system was implemented made clear some of the most prevalent issues which convinced ODOT to pursue VSL. Using those issues as a basis, a framework of seven specific evaluation questions relating to both performance and safety, as well as both congestion and adverse weather, was established to guide the "before and after" comparisons. Hypotheses, and measures of effectiveness for each question were developed, and data were obtained from a diverse array of sources including freeway detectors, ODOT's incident database, and the National Oceanic and Atmospheric Administration (NOAA). The results of the various "before and after" comparisons performed as a part of this thesis indicate that conditions have changed on OR 217 in a number of ways since the VSL system was activated. Many, but not all, of the findings were consistent with the initial hypotheses and with the findings from other VSL studies in the literature. Certain locations along the corridor have seen significant declines in speed variability, supporting the common notion that VSL systems have a harmonizing effect on traffic flow. Crash rates have not decreased, but crashes have become less frequent in the immediate vicinity of VSL signs. Flow distribution between adjacent lanes has been more even since VSL implementation during midday hours and the evening peak, and travel time reliability has seen widespread improvement in three of the corridor's four primary travel lanes during those same times. The drops in flow that generally occur upstream of bottlenecks once they form have had diminished magnitudes, while the drops in flow downstream of the same bottlenecks have grown. Finally, the increase in travel times that is usually brought about by adverse weather has been smaller since VSL implementation, while the decline in travel time reliability has largely disappeared.