Low speed urban streets are designed to provide both access and mobility, and accommodate multiple road users, such as bicyclists and pedestrians. However, speeds on these facilities often exceed the intended operating speeds as well as their design speeds. Several studies have indicated that the design speed concept, as implemented in the roadway design process in the United States, does not guarantee a consistent alignment that promotes uniform operating speeds less than design speeds. To overcome these apparent shortfalls of the design speed approach, a promising design approach is a performance-based design procedure with the incorporation of operating speeds. Under this procedure, the geometric parameters of the roadways are selected based on their influences on the desired operating speeds. However, this approach requires a clear understanding of the relationships between operating speeds and various road environments. Although numerous studies have developed operating speed models, most of these previous studies have concentrated on high speed rural two-lane highways. In contrast, highway designers and planners have very little information regarding the influence of low speed urban street environments on drivers' speeds. This dissertation investigated the relationship between drivers' speed choices and their associated low speed urban roadway environments by analyzing second-by-second in-vehicle GPS data from over 200 randomly selected vehicles in the Atlanta, Georgia area. The author developed operating speed models for low speed urban street segments based on roadway alignment, cross-section characteristics, roadside features, and adjacent land uses. The author found the number of lanes per direction of travel had the most significant influence on drivers' speeds on urban streets. Other significant variables include on-street parking, sidewalk presence, roadside object density and offset, T-intersection and driveway density, raised curb, and adjacent land use. The results of this research effort can help highway designers and planners better understand expected operating speeds when they design and evaluate low speed urban roadways.

One of the significant weaknesses of the design speed concept is that it uses the design speed of the most restrictive geometric element as the design speed of the entire road. This leads to potential inconsistencies among successive sections of a road. Previous studies documented that a uniform design speed does not guarantee consistency on rural two-lane facilities. It is therefore reasonable to assume that similar inconsistencies could be found on rural four-lane non-freeway highways. The operating speed-based method is popularly used in other countries for examining design consistency. Numerous studies have been completed on rural two-lane highways for predicting operating speeds. However, little is known for rural four-lane non-freeway highways. This study aims to develop operating speed prediction models for horizontal curves on rural four-lane non-freeway highways using 74 horizontal curves. The data analysis showed that the operating speeds in each direction of travel had no statistical differences. However, the operating speeds on inside and outside lanes were significantly different. On each of the two lanes, the operating speeds at the beginning, middle, and ending points of the curve were statistically the same. The relationships between operating speed and design speed for inside and outside lanes were different. For the inside lane, the operating speed was statistically equal to the design speed. By contrary, for the outside lane, the operating speed was significantly lower than the design speed. However, the relationships between operating speed and posted speed limit for both inside and outside lanes were similar. It was found that the operating speed was higher than the posted speed limit. Two models were developed for predicting operating speed, since the operating speeds on inside and outside lanes were different. For the inside lane, the significant factors are: shoulder type, median type, pavement type, approaching section grade, and curve length. For the outside lane, the factors included shoulder type, median type, approaching section grade, curve length, curve radius and presence of approaching curve. These factors indicate that the curve itself does mainly influence the drivers speed choice.

Gegenstand dieser Arbeit ist die Entwicklung von Methoden zur Synthese und Umsetzung optimaler Bewegungen in Verarbeitungsmaschinen. Bewegungen werden zur Steuerung von Arbeitsorganen eingesetzt und müssen im Rahmen einer Maschinenentwicklung synthetisiert werden. Sowohl die Qualität der Bewegung als auch deren Umsetzung hat wesentlichen Einfluss auf den Erfolg des Verarbeitungsprozesses sowie auf die tatsächliche Maschinenausbringung. Besondere Beachtung wird bei der Methodenentwicklung auf den Aspekt der einstellbaren Drehzahl einer Verarbeitungsmaschine gelegt. Aufbauend auf einer Darstellung sowie Abgrenzung des wissenschaftlichen Fachgebietes werden die spezifischen Anforderungen an Bewegungen in modernen Verarbeitungsmaschinen diskutiert. In diesem Zusammenhang werden die in Wissenschaft und Technik bekannten Methoden und Vorgehensweisen demonstriert, ihre Vor- und Nachteile diskutiert sowie deren Anwendungsgrenzen ermittelt. Diese Grenzen betreffen im Wesentlichen die bisher vernachlässigte Drehzahlabhängigkeit optimaler Bewegungen, welche den effektiven Drehzahlbereich limitiert und mithin auch die Maschinenausbringung. Hieraus ergibt sich die technisch-wissenschaftliche Problemstellung, zu deren Lösung diese Arbeit beitragen soll. Zur Lösung der Problemstellung werden Beispiele von Verarbeitungsaufgaben diskutiert, bei denen drehzahlabhängiges Verhalten festzustellen ist und welches Einfluss auf die Ausbringung der Verarbeitungsmaschine hat. Aus dieser Analyse resultiert die Auswahl der Verarbeitungsaufgabe Fluidtransport als repräsentatives Beispiel, das auf Grund seiner Eigenschaften zur Demonstration aller Überlegungen und Methoden geeignet ist. Grundlage für die Bewegungsoptimierung, die die Lösung der Bewegungsaufgabe für verschiedene eingestellte Drehzahlen liefert, ist ein valides Prozessmodell, das zur Beantwortung prozessspezifischer Fragestellungen befähigt. Auf Grundlage von in Experimenten gewonnenen Informationen werden Prozessmodelle unter Berücksichtigung der variablen Drehzahl sowie des Formates abgeleitet und die dazugehörigen Modellgrenzen ermittelt. Mit Hilfe dieser Modelle werden unter Nutzung der Methode der optimalen Steuerung optimale Bewegungen ermittelt, wobei auch deren Robustheit gegenüber Veränderungen der Modellparameter betrachtet wird. In einem letzten Schritt wird untersucht, wie die von der eingestellten Maschinendrehzahl abhängigen optimalen Bewegungen mittels moderner Antriebstechnik umgesetzt werden können. Hierzu wird das Konzept des Bewegungskennfeldes angewandt, das es erlaubt, unter Vorgabe einer endlichen Anzahl von Bewegungen, Vorgaben für beliebige Drehzahlen in Echtzeit bereitzustellen. Zur Bewertung der entwickelten Methoden werden die Ergebnisse aller Teilschritte mit Ergebnissen verglichen, die sich aus Methoden des Standes von Wissenschaft und Technik ergeben. Den Abschluss bildet eine Zusammenfassung der Arbeit sowie eine Einordnung der erlangten Erkenntnisse in das Wissenschaftsgebiet. Weiterhin werden die aus dieser Arbeit abgeleiteten neuen Forschungsfragen präsentiert und mögliche Lösungsansätze für deren Beantwortung gegeben. / Subject of this thesis is the development of methods for the synthesis and implementation of optimal motions in processing machines. Motions are used to control working tools and have to be synthesized during a machine development. The quality of the motion as well as its implementation has a significant influence on the success of the process as well as on a machines effective output range. Special attention is paid to the aspect of the adjustable operating speed of the processing machine during the development of methods. The specific requirements for motions in modern processing machines are discussed based on a description and delimitation of the scientific field. In this context the methods and procedures known in science and technology are demonstrated, their advantages and disadvantages are discussed and their application limits are determined. These limits mainly concern the so far neglected speed dependency of optimal motions, which limits the effective speed range and consequently also the machine output. This results in the technical-scientific problem definition, to whose solution this thesis shall contribute. For this purpose, examples of processing tasks are discussed, where speed-dependent behavior can be determined and which influence the output of the processing machine. This analysis results in the selection of the processing task fluid transport as a representative example, which is suitable for demonstrating all considerations and methods due to its properties. The basis for the motion optimization, which allows the solution of the motion task for different set speeds, is a valid process model that is capable of answering process-specific questions. On the basis of information obtained in experiments, process models are derived taking into account the variable speed as well as format size. The corresponding model limits are determined. With the help of these models, optimal motions are determined using the optimal control method, whereby their robustness against fluctuations of the model parameters is also considered. In a final step, it is investigated how the optimal motions, which depend on the set machine speed, can be implemented by means of modern drive technology. For this purpose, the concept of the characteristic motion map is applied, which allows to provide presets for arbitrary speeds in real time by specifying a finite number of motions. To evaluate the developed methods, the results of all sub-steps are compared with results obtained by state-of-the-art methods. The conclusion is a summary of the thesis and a classification of the knowledge gained within the scientific field. Furthermore, the new research questions derived from this thesis are presented and a outlook for their solutions is given.

The subject of this splitted article is the commissioning of a new application that may be part of a processing machine. At the example of the intermittent transport of small sized goods, for example, chocolate bars, ideas for increasing the maximum machine performance are discussed. Therefore, optimal process motion profiles are synthesised with the help of a computer simulation. In the first part of the paper, the modelling of the process was shown. This second part focusses on implementing the simulated motion approaches on an experimental test rig, whereby the new motion approach is compared to the conventional approach. Hence, the increasing of the performance can be proven. Eventually, possibilities for an online process control are observed which are necessary to prevent unstable process conditions.

The subject of this splitted article is the commissioning of a new application that may be part of a processing machine. At the example of the intermittent transport of small sized goods, for example, chocolate bars, ideas for increasing the maximum machine performance are discussed. Therefore, optimal process motion profiles are synthesised with the help of a computer simulation. In the first part of the paper, the modelling of the process was shown. This second part focusses on implementing the simulated motion approaches on an experimental test rig, whereby the new motion approach is compared to the conventional approach. Hence, the increasing of the performance can be proven. Eventually, possibilities for an online process control are observed which are necessary to prevent unstable process conditions.

This diploma thesis deals with the relation between the longitudinal friction coefficient dependence on measuring speed and the value of road surface macrotexture MPD. Results of longitudinal friction coefficient and value of MPD measurement on 73 sections are included in this thesis. The results were compared by regression analysis and its outcome was used for determination of formula that enable calculation of longitudinal friction coefficient for any operating speed when longitudinal friction coefficient for 60 km/h and value of macrotexture are known. The evaluation scale for skid resistance index (SRI) was also determined in this thesis. It could be used for evaluation of skid resistance independently of the type of device used for friction coefficient measurement.

Road safety is one of the most important problems in our society. It causes hundreds of fatalities every year worldwide. A road accident may be caused by several concurrent factors. The most common are human and infrastructure. Their interaction is important too, which has been studied in-depth for years. Therefore, there is a better knowledge about the driving task. In several cases, these advances are still not included in road guidelines. Some of these advances are centered on explaining the underlying cognitive processes of the driving task. Some others are related to the analysis of drivers’ response or a better estimation of road crashes. The concept of design consistency is related to all of them. Road design consistency is the way how road alignment fits drivers’ expectancies. Hence, drivers are surprised at inconsistent roads, presenting a higher crash risk potential. This PhD presents a new, operating speed-based global consistency model. It is based on the analysis of more than 150 two-lane rural homogeneous road segments of the Valencian Region (Spain). The final consistency parameter was selected as the combination of operational parameters that best estimated the number of crashes. Several innovative auxiliary tools were developed for this process. One example is a new tool for recreating the horizontal alignment of two-lane rural roads by means of an analytic-heuristic process. A new procedure for determining road homogeneous segments was also developed, as well as some expressions to accurately determine the most adequate design speed. The consistency model can be integrated into safety performance functions in order to estimate the amount of road crashes. Finally, all innovations are combined into a new road design methodology. This methodology aims to complement the existing guidelines, providing to road safety a continuum approach and giving the engineers tools to estimate how safe are their road designs. / Camacho Torregrosa, FJ. (2015). DEVELOPMENT AND CALIBRATION OF A GLOBAL GEOMETRIC DESIGN CONSISTENCY MODEL FOR TWO-LANE RURAL HIGHWAYS, BASED ON THE USE OF CONTINUOUS OPERATING SPEED PROFILES [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/48543