New methods for travel time estimation on freeway sections

In this paper we present two novel approaches to estimate the travel times between subsequent detector stations in a freeway network, with long distances between detector stations and several unobserved on- and off-ramps. The network under investigation is a two-lane freeway. The maximum distance between detector stations, for which travel times were estimated is about 20 km with four unobserved on- and off-ramps in between. The algorithms were applied on real data sets, which has led to reasonable estimates. However, due to unknown actual ('true') travel times, a performance assessment was not possible. The algorithms were also applied on simulated data with known travel times. This allowed the verification of the estimated travel times. The simulated data were generated by the microscopic traffic simulation tool AIMSUN NG®. The detector stations were assumed to be equipped with widespread double loop detectors, i.e., for each vehicle, the only information used was its length (with a superimposed measurement noise) and the arrival time at the detector stations. The estimated travel times show that with both methods all relevant travel time characteristics were correctly identified for the investigated scenarios. Moreover, a comparison of the estimates with the actual travel times has shown very good accuracy. Besides the fact that the methods work well even under hindered conditions (long distance, unobserved ramps), some additional practical benefits are: provided that single car data are available with sufficient accuracy, no additional investments are required; both methods work fully anonymous; extensions to more sophisticated detection technologies that provide additional vehicle features are straightforward; the travel time estimates form a good basis for any travel time prediction method.In diesem Beitrag stellen wir zwei neue Verfahren zur Reisezeitschätzung zwischen aufeinander folgenden Zählstellen auf Autobahnen vor. Das dabei untersuchte Netzwerk ist eine zweispurige Autobahn. Die maximale Distanz zwischen den Zählstellen, für welche Reisezeitschätzungen erfolgen, ist dabei bis zu 20 km lang mit je vier nicht beobachteten Ein- und Ausfahrten dazwischen. Die Algorithmen wurden auf reale Daten angewendet, wobei sich plausible Reisezeiten ergaben. Ein Problem war dabei jedoch, dass zum tatsächlichen Vergleich keine "wahren" Reisezeiten zur Verfügung standen. Da Vergleichswerte für die Bewertung der Verfahren unumgänglich sind, wurden verschiedene Verkehrssituationen mit dem Mikrosimulationstool AIMSUN NG® simuliert. Dadurch waren genaue Referenzdaten verfügbar und die Schätzungen konnten damit verglichen werden. Aufgrund der Tatsache, dass die Zählstellen auf dem Schweizer Nationalstrassennetz vorwiegend mit Doppelinduktionsschleifen ausgerüstet sind, wurde dies auch für die simulierten Szenarien angenommen. Dies wurde erreicht, indem zur tatsächlichen Fahrzeuglänge für jedes Fahrzeug an jeder Zählstelle jeweils ein zufälliger Messfehler addiert wurde. Als Input für die Verfahren wurden also für jedes genierte Fahrzeug an den Zählstellen lediglich die fehlerbehaftete Länge und der Durchfahrtszeitpunkt ermittelt. Beide Verfahren konnten für die untersuchten Szenarien alle relevanten Reisezeit-Charakteristiken korrekt identifizieren. Zudem zeigte ein Vergleich mit den Referenzdaten, dass sich für beide Verfahren sehr gute Genauigkeiten ergaben. Nebst der Tatsache, dass die Methoden auch unter erschwerten Bedingungen (grosse Distanzen, unbeobachtete Ein- und Ausfahrten) funktionieren, ergeben sich einige zusätzliche Vorteile: Vorausgesetzt, dass Einzelfahrzeugdaten in ausreichender Qualität zur Verfügung stehen, sind keine zusätzlichen Infrastruktur-Investitionen nötig. Desweiteren sind beide Verfahren vollständig anonym, es sind also keine Rückschlüsse auf einzelne Fahrzeuge möglich. Beide Verfahren erlauben es zudem, Messdaten von Verfahren zu nutzen, welche weitere Fahrzeug-Eigenschaften extrahieren können (z.B. Höhe, Breite). Schliesslich bilden die mit diesen Verfahren gewonnenen Reisezeitschätzungen eine gute Basis für nachfolgende Algorithmen zur Reisezeitprognose.In this paper we present two novel approaches to estimate the travel times between subsequent detector stations in a freeway network, with long distances between detector stations and several unobserved on- and off-ramps. The network under investigation is a two-lane freeway. The maximum distance between detector stations, for which travel times were estimated is about 20 km with four unobserved on- and off-ramps in between. The algorithms were applied on real data sets, which has led to reasonable estimates. However, due to unknown actual ('true') travel times, a performance assessment was not possible. The algorithms were also applied on simulated data with known travel times. This allowed the verification of the estimated travel times. The simulated data were generated by the microscopic traffic simulation tool AIMSUN NG®. The detector stations were assumed to be equipped with widespread double loop detectors, i.e., for each vehicle, the only information used was its length (with a superimposed measurement noise) and the arrival time at the detector stations. The estimated travel times show that with both methods all relevant travel time characteristics were correctly identified for the investigated scenarios. Moreover, a comparison of the estimates with the actual travel times has shown very good accuracy. Besides the fact that the methods work well even under hindered conditions (long distance, unobserved ramps), some additional practical benefits are: provided that single car data are available with sufficient accuracy, no additional investments are required; both methods work fully anonymous; extensions to more sophisticated detection technologies that provide additional vehicle features are straightforward; the travel time estimates form a good basis for any travel time prediction method

A new method for travel time estimation on long freeway sections

The knowledge of travel times on road networks is of vital importance for network operators as well as for drivers. Operators can use travel time information to improve control on their networks. Drivers or transport companies can choose their optimal route based on the traffic information available and their individual preferences. The presented approach focuses on travel time estimation. The method only requires the time stamps and vehicle lengths captured at subsequent detector stations. The distance between the stations is up to 13 km. The examined network is a two-lane freeway with three unobserved on- and off-ramps each. In order to investigate the influence of measurement errors and to have true data for comparison, simulated detector data based on an existing Swiss freeway section equipped with loop detectors was used. The method shows very good performance for the investigated scenarios. All relevant characteristics of the travel time process were detected and estimation errors were within a well acceptable range. Compared to existing travel time estimation methods, the presented approach considerably extends the maximum distance for which travel time estimations can be carried out

Simulation based case studies for management training in the fields of production and supply chain Management

It is well known that interactive learning is much more efficient than classical learning with textbooks. With the broad propagation of computers, new opportunities for computer-based interactive learning are available. In particular, simulation based learning allows the student to learn based on experience. In economic and technical environments, where complex systems comprise numerous decision variables, conducting experiments can provide a deeper insights and an intuitive understanding to the student. In the present paper, a newly developed environment for computer-based interactive learning in the fields of production and supply chain training is described. The different steps from the evaluation of an appropriate electronic platform to the development of eight different case studies for the students are explained. The environment now provides an easily applicable and ready-to-use solution for university teachers and their students

Kundenfreundliche und robuste Ersatzfahrpläne während Bau- und Unterhaltsintervallen

An der ZHAW wurde ein Verfahren entwickelt, um in kürzester Zeit Ersatzfahrpläne für Bau- und Unterhaltsintervalle zu erstellen – ein für den stabilen Bahnbetrieb zunehmend wichtiges Thema. Die Methode berücksichtigt nicht nur betriebliche Aspekte wie die temporären Einschränkungen der Bahnanlage, sondern stellt gleichzeitig auch den Kundennutzen ins Zentrum der Planung. Dadurch kann das beste Transportangebot in Bezug auf Reisezeiten und Zuverlässigkeit realisiert werden

Les futurs enseignants et la créativité: quelles conceptions ?

Cette contribution présente les résultats obtenus dans le cadre d’une recherche menée par la Haute école pédagogique fribourgeoise (HEP-FR) et visant à capter les conceptions des étudiants au sujet de la créativité. Ce travail, basé sur la passation d’un questionnaire traduit et adapté de Diakidoy et Kanari (1999) et sur une série d’entretiens semi-dirigés menés avec des étudiants ayant développé des séquences d’enseignement – apprentissage en éducation musicale autour de la créativité lors d’un stage d’enseignement, met en évidence un enchevêtrement de conceptions plus ou moins antithétiques ainsi qu’un relatif désintérêt du processus créatif au profit du produit final

A psychological framework to enable effective cognitive processing in the design of emergency management information systems

Human cognitive processing and decision making are essential aspects in emergency management. Emergency situations imply additional demands to information processing. To meaningfully support decision makers in emergencies, a comprehensive understanding of the human perception and decision making processes and their underlying principles is required in the design of Emergency Management Information Systems (EMIS).This paper presents a psychological framework that models the stages and components of decision making in the context of emergency management. To this end, psychological research on human perception and information processing, knowledge and competence modelling, human judgement and decision making, individual and situational factors, stress, and self-regulation are identified as important compents of the framework. The psychological framework represents a comprehensive model of decision making of emergency managers, for a better understanding of the involved cognitive processes and influencing factors on the person level and on the context level. The paper posits the framework as a guide in the identification of requirements for emergency managers during systems analysis. This comprises systematically describing decision tasks in emergency situations and identifying needs for supporting them. The knowledge on human perception and decision making represented by the framework can also be used to inform the user interface design of the EMIS. It may also inform the evaluation of EMIS as it provides a theoretically founded representation of relevant aspects of human-computer interaction, which facilitates the identification of success indciators to be addressed in user-centred evaluation. The framework furthermore supports the design and implementation of training programmes through the differentiation and modelling of knowledge and competence relevant in emergency decision making. To demonstrate the application of the psychological framework in the design, development, and testing of EMIS a set of concrete design principles as well as exemplary paper prototypes applying these principles are presented

Development of a prototype for the automated generation of timetable scenarios specified by the transport service intention

Within the next 5 to 10 years, public transport in Switzerland as well as in other European countries will experience major technological and organisational changes. However, changes will also take place on the customer side, resulting in different mobility behaviour and demand patterns. These changes will lead to additional challenges for transport service providers in private as well as public domains. Time to market will be a key success factor and it is unnecessary to mention that due to these factors the speed and flexibility of business processes in freight as well as in passenger transport industry have to be increased significantly. Within the railway value chain (line planning, timetabling and vehicle scheduling etc.) the coordination of the individual planning steps is a key success factor. SBB as the leading service provider in public transport in Switzerland has recognized this challenge and, together with various partners, initiated the strategic project Smart Rail 4.0. The ZHAW and especially the Institute for Data Analysis and Process Design (IDP) of the School of Engineering wants to be part of this transformation process and to contribute with research and educational activities. The IDP research therefore aims for the transformation of academic and scientific know-how to practical applicability. In a first step this concerns directly the current Smart Rail 4.0 TMS-PAS project activities, that concentrate on timetabling issues. The IDP project team considers the integration of the line planning and the timetabling process as crucial for practical applications. To address this in the current research project, we present an application concept that enables the integration of these two major process steps in the transport service value-chain. Although it turns out from our research, that the technical requirements for the integration of the process can be satisfied, rules and conditions for a closer cooperation of the involved business units, the train operating companies and the infrastructure operating company, have to be improved and to be worked out in more detail. In addition to a detailed application concept with use cases for the timetabling process we propose a methodology for computer aided timetable generation based on the central planning object known as ‘service intention’. The service intention can be used to iteratively develop the timetable relying on a ‘progressive feasibility assessment’, a feature that is requested in practice. Our proposed model is based on the ‘track-choice’ and line rotation extension of the commonly known method for the generation of periodic event schedules ‘PESP’. The extension makes use of the track infrastructure representation which is also used in the line planning and timetabling system Viriato. This system that is widely used by public transport planners and operators. With the help of Viriato, it is rather easy to configure the timetabling problem in sufficient detail. On the other side, the level of detail of the considered data is light enough to algorithmically solve practical timetabling problems of realistic sizes. Taking into consideration the technical and operational constraints given by rolling stock, station and track topology data on one hand, and the commercial requirements defined by a given line concept on the other, the method presented generates periodic timetables including train-track assignments. In the first step, the standardized data structure ‘service intention’ represents the line concept consisting of train paths and frequencies. Due to the utilization of infrastructure-based track capacities, we are also able to assess the feasibility of the line concept given. Additionally, the method allows for handling temporary resource restrictions (e.g. caused by construction sites or operational disturbances). In order to assess the performance of the resulting timetable we present a framework for performance measurement that addresses the customer convenience (in terms of start-to-end travel time) as well as operational stability requirements (in terms of delay sensitivity and critical relations)

A novel approach and software component for supporting competence-based learning with serious games

Digital educational games constitute a major opportunity for acquiring knowledge and competences in a different way than traditional classroom- and technology-based methods. This paper presents a novel approach for a game component that structures the game play in an adaptive way. This approach consists of a combination of three learning theories and techniques. First, Competence-based Knowledge Space Theory is used structure a knowledge domain into competences and game situations. Second, the Leitner system of flashcards is used to establish structured and timed repetition of competences to be acquired. Third, the Ebbinghaus forgetting curve is taken into account to model forgetting learned competences. This approach has been implemented as a game component in line with the games component architecture of the RAGE project. The design and development of this component followed the requirements of the French games company Kiupe that includes it in its environment of games and mini-games

Improvement of maintenance timetable stability based on iteratively assigning event flexibility in FPESP

In the operational management of railway networks, an important requirement is the fast adaptation of timetable scenarios, in which operational disruptions or time windows with temporary unavailability of infrastructure, for instance during maintenance time windows, are taken into consideration. In those situations, easy and fast reconfiguration and recalculation of timetable data is of central importance. This local and temporal rescheduling results in shifted departure and arrival times and sometimes even in modified stop patterns at intermediate stations of train runs. In order to generate reliable timetabling results it is a prerequisite that train-track assignments, as well as operational and commercial dependencies are taken into consideration. In order to refer to the right level of detail for modelling track infrastructure and train dynamics in the computer aided planning process we present a generic model that we call Track-Choice FPESP (TCFPESP), as it implements suitable extensions of the established PESP-model. We show, how the service intention (the data structure for timetable specification) together with resource capacity information entered into a standard timetabling tool like Viriato can be utilized in order to configure the TCFPESP model. In addition, we are able to calculate quantitative performance measures for assessing timetable quality aspects. In order to achieve this we present a method for evaluating travel times based on passenger routings and a method for evaluating timetable robustness based on max-plus algebra. This approach supports the planner to generate integrated periodic timetable solutions in iterative development cycles and taking into account intervals for local maintenance work