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  • 1. Anand, N.
    et al.
    Anayi, Michel
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Improving punctuality of train traffic on Western main line of Swedish railway network: Simulation approach2010In: Proceedings Of The ASME Rail Transportation Division Fall Conference 2009, ASME Press, 2010, p. 15-24Conference paper (Refereed)
    Abstract [en]

    Western main line is one of the most important railway lines in Sweden. The line section from Stockholm to Katrineholm, which connects the largest cities of the Sweden i.e. Stockholm, Gothenburg and Malmö, is studied. This line has heterogeneous train traffic consisting high-speed, regional, freight and commuter trains. This paper attempts to study different factors affecting punctuality on this railway line concentrating on traffic problem around Gnesta station and commuter train turn-back scenario - a bottleneck - at the same station. Simulation of existing and modified timetable is done using train traffic simulation software "Railsys". Experiments including examining effect of rescheduling train timings, capacity enhancement and infrastructure changes in rail network are conducted and investigated. Robustness analysis is performed from the results of simulation and investigation of the consequences of delays and comparison of how different features in the timetables affect the robustness is done.

  • 2. Antoniou, C
    et al.
    Balakrishna, R
    Koutsopoulos, Haris
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Emerging Data Collection Technologies and their Impact on Traffic Management Applications2008Conference paper (Refereed)
  • 3. Antoniou, C.
    et al.
    Balakrishna, R.
    Koutsopoulos, Haris
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Exploiting emerging data collection technologies for dynamic traffic management applications2010In: Proceedings of World Conference on Transport Research (WCTR), 2010Conference paper (Refereed)
    Abstract [en]

    Several existing and emerging surveillance technologies are being used for traffic datacollection. Each of these technologies has different technical characteristics and operatingprinciples, which determine the types of data collected, accuracy of the measurements,levels of maturity, feasibility and cost, and network coverage. This paper reviews the differentsources of traffic surveillance data currently employed, and the types of traffic managementapplications they may support. The current state-of-the-art of traffic modeling is alsodiscussed, in the context of using emerging data sources for better planning, operations anddynamic management of road networks.

  • 4.
    Archer, Jeffery
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics, Traffic and Logistics. KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Indicators for traffic safety assessment and prediction and their application in micro-simulation modelling: a study of urban and suburban intersections2005Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    In order to achieve sustainable long-term transport infrastructure development, there is a growing need for fast, reliable and effective methods to evaluate and predict the impact of traffic safety measures. Recognising this need, and the need for an active traffic safety approach, this thesis focuses on traffic safety assessment and prediction based on the use of safety indicators that measure the spatial and/or temporal proximity of safety critical events. The main advantage of such measures is that they occur more frequently than accidents, and therefore require relatively short periods of study to establish values that can later be used for comparison, or for accident prediction purposes. There are a number of more generally accepted safety indicators including: Time-to-Accident, Time-to-Collision, and Post-Encroachment Time. These are based on different underlying principles and measurement techniques, including both on-site subjective estimation, and objective photometric measures.

    A major part of the work presented in this thesis, concerns identifying the potential and limitations of the different safety indicators with regard to their validity and reliability, and practical use for safety assessment and prediction purposes. This is done in conjunction with field studies in the urban and suburban environment, at both signalised and unsignalised intersections. Results from these studies indicate that on-site observation methods provide useful quantitative and qualitative information relatively quickly and efficiently, provided that they are used correctly. On the other hand, the methods based on photometric measurement (video-analysis) proved arduous and time-consuming. Furthermore, there are questions regarding the abilities of the Time-to-Collision and Post-Encroachment Time safety indicators to adequately represent interaction severity, suggesting possible flaws in fundamental concepts related to construct validity. Importantly, results showed that the relationship between safety indicators and traffic accidents is complex and equivocal, where many different factors and processes can impose a significant influence on safety. This makes generalised predictive modelling a particularly difficult task for safety analysts.

    The potential of micro-simulation for traffic safety and performance estimation based on the use of safety indicators was investigated in the second part of this thesis. Microscopic traffic simulation has become increasingly popular among transport planners, due to the fact that it serves as a safe and flexible off-line test environment for the estimation of dynamic and complex traffic system effects. It is useful and cost-effective in relation to the evaluation of issues concerning roadway design, and technological systems that influence road-user behaviour and vehicle performance. For reasons related to modelling fidelity and data quality, simulation has seldom been used for traffic safety estimation. Simulation model development is however, undergoing rapid development and the area of ‘safety-simulation’ and is recognised as having a high potential in the field of transport planning and traffic engineering.

    As part of the work in this thesis, practical simulation experiments were carried out to investigate this potential, and identify limitations. Based on the data from one of the earlier studies, and knowledge regarding important safety-influencing factors and behavioural processes, one of the simulation experiments showed evidence to suggest that realistic safety critical events could be generated and measured using safety indicators in a simulation environment, without making unnecessary and unrealistic behavioural assumptions. Furthermore, a second application of this methodology revealed the safety potential of a rear-end incident-reduction function used in standard vehicle actuated signalling. While both of these simulation studies highlighted the potential of this type of approach, the need for more flexible and realistic models of interactive behavioural processes could be identified in addition to the general need for greater active research into the field of safety simulation.

  • 5. Balakrishna, R.
    et al.
    Ben-Akiva, Moshe
    Koutsopoulos, Haris
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Time-Dependent Origin-Destination Estimation Without Assignment Matrices2008In: Traffic Simulation, EPFL Press , 2008Conference paper (Refereed)
    Abstract [en]

    Time-dependent origin-destination (OD) flows are crucial inputs to dynamic traffic assignment (DTA) models. However, they are often unobserved, and must be estimated from indirect traffic measurements collected from the study network. Approaches to estimate OD flows from link counts traditionally rely on assignment matrices that map the OD flow variables onto the counts. However, this method (a) approximates the complex relationship between OD flows and counts with a linear function, (b) is restricted to the use of only counts, and cannot exploit richer data such as speeds, densities or travel times, and (c) cannot estimate route choice and supply parameters that critically impact the OD estimates. We present a dynamic OD estimation method that is accurate, flexible in the use of general traffic data, simultaneously estimates all parameters that impact OD estimation, and can be applied to any traffic assignment model.

  • 6. Balakrishna, R
    et al.
    Koutsopoulos, Haris
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Incorporating Within-Day Transitions in Simultaneous Estimation of Dynamic Origin-Destination Flows Without Assignment Matrices2008Conference paper (Refereed)
  • 7. Balakrishna, R
    et al.
    Koutsopoulos, Haris
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Simultaneous Calibration of Dynamic Origin-Destination Matrices with Structural Relationships2008Conference paper (Refereed)
  • 8. Balakrishna, Ramachandran
    et al.
    Koutsopoulos, Haris N.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Incorporating Within-Day Transitions in Simultaneous Offline Estimation of Dynamic Origin-Destination Flows Without Assignment Matrices2008In: Transportation Research Record, ISSN 0361-1981, E-ISSN 2169-4052, no 2085, p. 31-38Article in journal (Refereed)
    Abstract [en]

    An offline methodology is presented: it simultaneously estimates dynamic origin-destination (O-D) matrices, without using assignment matrices that incorporate within-day transition equations. The proposed formulation and solution approach extends a calibration method recently developed that directly uses the output of any network loading model (such as a dynamic traffic assignment or simulation model) so that the complex relationships between O-D flows and model outputs are accurately captured (as opposed to the more common method of approximate linear relationships based oil file assignment matrix). The study extends the original formulation by incorporating spatial and temporal relationships among various O-D flows (transition equations). These transition equations link O-D flow variables across time intervals in such it way that known structural demand patterns can be preserved in the new estimates. Such transition equations, although common in the context of real-time O-D flows, complicate the offline simultaneous estimation of O-D flows and have not been used to their full potential in the past. The approach is demonstrated through a case study.

  • 9. Biem, Alain
    et al.
    Bouillet, Eric
    Feng, Hanhua
    Ranganathan, Anand
    Riabov, Anton
    Verscheure, Olivier
    Koutsopoulos, Haris
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Moran Toledo, Carlos
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    IBM InfoSphere Streams for Scalable, Real-Time, Intelligent Transportation Services2010In: 2010 International Conference on Management of Data, SIGMOD '10, 2010, p. 1093-1103Conference paper (Refereed)
    Abstract [en]

    With the widespread adoption of location tracking technologies like GPS, the domain of intelligent transportation services has seen growing interest in the last few years. Services in this domain make use of real-time location-based data from a variety of sources, combine this data with static location-based data such as maps and points of interest databases, and provide useful information to end-users. Some of the major challenges in this domain include i) scalability, in terms of processing large volumes of real-time and static data; ii) extensibility, in terms of being able to add new kinds of analyses on the data rapidly, and iii) user interaction, in terms of being able to support different kinds of one-time and continuous queries from the end-user. In this paper, we demonstrate the use of IBM InfoSphere Streams, a scalable stream processing platform, for tackling these challenges. We describe a prototype system that generates dynamic, multi-faceted views of transportation information for the city of Stockholm, using real vehicle GPS and road-network data. The system also continuously derives current traffic statistics, and provides useful value-added information such as shortest-time routes from real-time observed and inferred traffic conditions. Our performance experiments illustrate the scalability of the system. For instance, our system can process over 120000 incoming GPS points per second, combine it with a map containing over 600,000 links, continuously generate different kinds of traffic statistics and answer user queries.

  • 10. Biem, Alain
    et al.
    Bouillet, Eric
    Ranganathan, Anand
    Rahmani, Mahmood
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Koutsopoulos, Haris
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Real-Time Traffic Information Management using Stream Computing2010Report (Other academic)
  • 11.
    Boysen, Hans
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Developments in railway freight transportation between Scandinavia and Germany2010In: Proceedings of the 6th SoNorA University Think Tank Conference, 2010Conference paper (Refereed)
    Abstract [en]

    This paper investigates recent and ongoing developments in freight transportation by railbetween Scandinavia and Germany. Present capacity constraints are identified. Infrastructureinvestment plans until about 2020 are reviewed. Technical standards between the national railwaynetworks are compared and common best practices are proposed. Among the conclusions arerecommendations to unify the operation of long freight trains, to raise axle loads and to adoptenlarged, flat-top loading gauges.

  • 12.
    Burghout, Wilco
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Cats, Oded
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Toledo, Tomer
    Koutsopoulos, Haris
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    DYMOBUS: dynamic mesoscopic modelling of bus public transport2009In: Conference proceedings to ITS 2009 conference, 2009Conference paper (Refereed)
    Abstract [en]

    In today’s public bus transport punctuality is one of the main problems to deal with for traffic planners and operators, especially in large cities such as Stockholm. The current static models do not handle congestion delays and the interaction between bus and car traffic, leading to overly optimistic timetables and hard to manage delays. In the DYMOBUS project (Funded by VINNOVA and City of Stockholm) a dynamic modelling tool was developed in order to study these interactions. This paper discusses a mesoscopic, mixed-traffic, a transit simulation model designed to support evaluation of operations planning and control, especially in the context of Advanced Public Transportation Systems (APTS). Examples of applications include frequency determination, evaluation of real time control strategies for schedule maintenance and restoration from major disruptions. The transit simulation component is designed to represent realistically the uncertainty in operations, in order to assess service reliability. The simulation models all sources of uncertainty: chaining of trips, travel time variability, behavior at stops and a detailed representation of passenger demand at the various stops. Unlike most previous efforts in this area, the simulation model is built on the platform of a mesoscopic traffic simulation model, which allows modeling of the operations of large-scale transit systems. A Tel-Aviv case study demonstrates the transit simulation capabilities of the model.

  • 13.
    Burghout, Wilco
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics.
    Koutsopoulos, Haris N.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics, Traffic and Logistics.
    Andreasson, Ingmar
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics.
    Incident Management and Traffic Information Tools and Methods for Simulation-Based Traffic Prediction2010In: Transportation Research Record, ISSN 0361-1981, E-ISSN 2169-4052, no 2161, p. 20-28Article in journal (Refereed)
    Abstract [en]

    Incident response and mitigation are among the main tasks of operators at traffic control centers. Simulation models have a good chance of reproducing and predicting the effects of incident response by explicitly modeling driver response to the incident and information provided. In the PREDIKT project sponsored by the Swedish National Road Administration, the state-of-the-art mesoscopic simulation model MEZZO was extended to provide decision support for incident management. Numerous essential modeling components are described and tested, including modeling the incident response logic, a mixed-logit model, and a method for generating alternatives for drivers switching routes. In addition, the results of a fast calibration method based on simultaneous perturbation statistic approximation are presented. The model components are tested in a small case study that investigates the effect of delay in providing information to drivers after incidents. A linearization of speed-density functions also is shown to improve computational performance by 30% and increase calibration speed and stability while preserving simulation accuracy.

  • 14.
    Cats, Oded
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    BusMezzo: dynamic modeling of bus and car traffic2010Conference paper (Other academic)
  • 15.
    Cats, Oded
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    DYMOBUS: Mesoscopic modeling of bus public transport2009Conference paper (Other academic)
  • 16.
    Cats, Oded
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    DYMOBUS: Transit simulation2010Conference paper (Refereed)
  • 17.
    Cats, Oded
    et al.
    Faculty of Civil and Environmental Engineering, Technion-Israel Institute of Technology, Haifa.
    Burghout, Wilco
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Toledo, Tomer
    Koutsopoulos, Harilaos
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Mesoscopic Modeling of Bus Public Transportation2010In: Transportation Research Record, ISSN 0361-1981, E-ISSN 2169-4052, no 2188, p. 9-18Article in journal (Refereed)
    Abstract [en]

    Analysis of public transport system performance and level of service in urban areas is essential. Dynamic modeling of traffic conditions, passenger demand, and transit operations is important to represent adequately the complexity of and the interactions between these components in modern public transportation systems. This paper presents a transit simulation model designed to support evaluation of operations planning and control, especially in the context of advanced public transportation systems. Unlike most previous efforts in this area, the simulation model is built on a platform of a mesoscopic traffic simulation model, which allows modeling or the operation dynamics of large-scale transit systems, taking into account the main sources of service uncertainty and stochasticity. The capabilities of Mezzo as an evaluation tool of transit operations are demonstrated with an application to a real-world, high-demand bus line in metropolitan Tel Aviv, Israel, under various scenarios. The application shows that important phenomena such as bus bunching are reproduced realistically. A comparison of simulated running times and headway distributions with field data shows the model is capable of replicating observed data.

  • 18.
    Cats, Oded
    et al.
    Faculty of Civil and Environmental Engineering, Technion-Israel Institute of Technology, Haifa.
    Burghout, Wilco
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Toledo, Tomer
    Koutsopoulos, Haris
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Mesoscopic modeling of bus public transportation2010Conference paper (Refereed)
  • 19.
    Chiguma, Masatu L. M.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Analysis of side friction impacts on urban roads: Case study Dar-es-Salaam2007Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    Side friction factors are defined as all those actions related to the activities taking place by the sides of the road and sometimes within the road, which interfere with the traffic flow on the travelled way. They include but not limited to pedestrians, bicycles, non-motorised vehicles, parked and stopping vehicles. These factors are normally very frequent in densely populated areas in developing countries, while they are random and sparse in developed countries making it of less interest for research and consequently there is comparatively little literature about them. The objective of this thesis is to analyze the effect of these factors on traffic performance measures on urban roads.

    To carry out this work, a research design was formulated including specific methods and prescribed limitations. An empirical case study methodology was adopted where Dar-es-salaam city in Tanzania was chosen as a representative case. The scope was limited to include only road-link facilities. A sample of these facilities including two-lane two-way and four-lane two-way roads were selected and studied. The study was conducted in two parts, of which each involved a distinctive approach. Part one involved a macroscopic approach where traffic and friction data were collected and analyzed at an aggregated level, whereas part two involved a microscopic approach where data of individual frictional elements were collected and analysed individually. Data collection was mainly performed by application of video method, which proved to be effective for simultaneous collection of traffic and side friction data. Data reduction was conducted chiefly by computer, using standard spreadsheet and statistical software packages, mainly SPSS and some computer macros.

    The analysis part was based on statistical methods, chiefly regression analysis. In the macroscopic approach, traffic and friction data from all sites were adjusted through a process called ‘normalization’, which enabled the data from the different sites to be merged, and consequently to obtain speed-flow curves for each road type. The individual friction factors through regression analysis were weighted and combined into one unit of measure of friction called "FRIC". The effect of "FRIC" on speed-flow curves was analyzed. The results showed significant impact on speed for both road types. Impact on capacity was identified on two-lane two-way roads while field data on four-lane two-way roads did not allow this. In the microanalysis approach, effect of individual side friction factors on speed was analyzed. The results showed that on two-lane two-way roads, all studied factors exhibited statistically significant impact on speed, while on four-lane two-way roads, only one factor showed the same. The results also identified impact values characteristic to the individual friction factors on some roads.

    Recommendations were made based on these results that highway capacity studies particularly in developing countries, should include the friction variable, though in the form suitable to their own particular circumstances. Further recommendations were made that these results should be applied to formulate management programs seeking to limit levels of side friction on high mobility urban arterial streets in order to improve traffic safety and operation efficiency.

  • 20.
    Dziekan, Katrin
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics, Traffic and Logistics.
    Ease-of-Use in Public Transportation: A User Perspective on Information and Orientation Aspects2008Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    This interdisciplinary thesis combines psychological and transportation planning knowledge. Three main questions are investigated: 1) What concepts and ideas do people have with regard to a public transportation system (cognitive user perspective)?; 2) What orientation and information factors within the public transportation system enhance Ease-of-Use and make it simpler and more efficient to use public transportation in metropolitan areas?; 3) How can Ease-of-Use of a public transportation route be measured?

    A combination of qualitative and quantitative methods was used. Between 2002 and 2007 a total of nine different studies were conducted: An in-depth study on a single exchange student, an interview study with exchange students, a questionnaire study on exchange students, a before-after interview study with travellers on selected bus stops, an before-after telephone interview study on residents, an expert questionnaire study via email, a behaviour observation study on travellers, a before-after questionnaire study on travellers on a tram line, and an on-board questionnaire study.

    To analyse the cognitive user perspective the term memory representation was introduced, that includes cognitive maps of and additional knowledge about a public transportation system such as service frequency. Memory representation is influenced by experience. Three learning phases in an unknown public transportation system are proposed and a general information search script is described. A new approach is presented regarding the organisation of public transportation knowledge: The ground level is that there exists a public transportation option, the next level is the identification of the mode of transport and at the highest level of the hierarchy is the code for the line. Within the second level, the public transportation mode, a hierarchical structure of public transportation option knowledge is proposed. Three factors are postulated that contribute to the extent to which a line is represented in people’s memory: visibility, straight route layout and labelling.

    Which orientation and information factors within the public transportation system enhance Ease-of-Use, i.e. match the cognitive user perspective? It was found that trunk bus lines enhanced Ease-of-Use and at-stop real-time information can have various positive effects. The role of good maps is explained and stretched and the importance of consistent information throughout the travel chain is also pointed out. In addition, many valuable concrete hints are given with regard to how to match the system properly with the cognitive user perspective. Undoubtedly, an interaction exists between system and user and they influence each other. This is where the third research question comes in: How can Ease-of-Use in public transportation systems be measured? The iterative process of defining and measuring Ease-of-Use resulted in a scale that measured the defined concept well with good reliability and validity. The final discussion highlights the contribution to science of this thesis and presents some possible paths for further research. The thesis consists of a summary and eight papers.

  • 21.
    Dziekan, Katrin
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics, Traffic and Logistics.
    Influence of a New Trunk Bus Route on the Memory Representation of Residents and Patronage2007In: Proceedings of World Conference on Transport Research (WCTR), 2007Conference paper (Refereed)
  • 22.
    Dziekan, Katrin
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics, Traffic and Logistics.
    The transit experience of newcomers to a city: learning phases, system difficulties and information search strategies2008In: Proceedings of the 87th TRB Meeting, 2008Conference paper (Refereed)
  • 23.
    Dziekan, Katrin
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics, Traffic and Logistics.
    What do people know about their public transport options?: Investigating the memory representation of public transport through telephone interviews in a residential area of Stockholm, Sweden2008In: Transportation, ISSN 0049-4488, E-ISSN 1572-9435, Vol. 35, no 4, p. 519-538Article in journal (Refereed)
    Abstract [en]

    This paper studies the memory representations of residents regarding the public transport system in their city. Telephone interviews were conducted with a representative sample of 204 inhabitants in a selected residential inner-city area in Stockholm. Route knowledge questions, recognition tasks, free-recall tasks and estimations of service frequency were used to explore memory representations. The results showed that, in general, residents in metropolitan areas have good knowledge of the public transport options along well-known transport corridors. The memory representation of lesser-known transport corridors tends to be of a poorer quality. In the results presented here, the variables gender, age, employment status, level of education and car availability had no correlation with the quality of the memory representation, but experience increased knowledge. Although frequent users of public transport had a more detailed representation of the system, the less frequent users also had a considerable- and good-memory representation. An explorative hierarchy for representation of public transport lines in the memory is proposed. It is hypothesised that memory representations of a transport line can be affected by the following three factors: the extent to which a line is visible in the urban area, the straightness of the routes and whether or not stops are labelled, for example, by destination area. Simply put, these factors determine how well a person knows a line. It was found that people first remember a commuter train and a trunk bus line, followed by metro lines and suburban buses and finally normal inner-city buses with the poorest anchorage in memory.

  • 24.
    Dziekan, Katrin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics, Traffic and Logistics.
    Dicke-Ogenia, M.
    Reducing uncertainty and supporting cognitive maps in travel information for public transport2010In: World Rewiew of Intermodal Transportation Research, ISSN 1749-4729, Vol. 3, no 1-2, p. 73-90Article in journal (Refereed)
    Abstract [en]

    One cause of negative attitudes towards public transport may be due to feelings of uncertainty that travellers experience. We argue that these negative feelings are due to a lack of information and that, in public transport, besides the regular service information, information should also be provided that helps to reduce uncertainty, i.e., information which supports the cognitive map of the traveller. This information should confirm that which is already present in the cognitive map, and should provide extra information about the transport system and the area in which it is used. We show the relevance of our argument by using research from several projects. Furthermore, we discuss the needs and wishes of travellers concerning travel information and the ergonomic principles involved in the design process of travel information.

  • 25.
    Dziekan, Katrin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics, Traffic and Logistics.
    Kottenhoff, Karl
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics, Traffic and Logistics.
    Dynamic At-stop Real-time Information Displays for Public Transport: Effects on Customers2007In: Transportation Research Part A: Policy and Practice, ISSN 0965-8564, E-ISSN 1879-2375, Vol. 41, no 6, p. 489-501Article in journal (Refereed)
    Abstract [en]

    Dynamic at-stop real-time information displays are becoming more and more ubiquitous in modern public transport. Reactions and attitudes towards these systems are very positive. But there is a need to provide a comprehensive framework of the possible effects that these kinds of displays can have on customers. The seven main effects described in this paper are: (A) reduced wait time, (B) positive psychological factors, such as reduced uncertainty, increased ease-of-use and a greater feeling of security, (C) increased willingness-to-pay, (D) adjusted travel behaviour such as better use of wait time or more efficient travelling, (E) mode choice effects, (F) higher customer satisfaction and finally (G) better image. Two studies are presented in this paper. Study I supports and proves that perceived wait times can be reduced by 20% by employing a before-after implementation evaluation study with questionnaires on a tramline. Study II shows the effects of real-time displays on behaviour in the form of adjusted walking speeds, by using a behaviour observation method in a subway station. The effect framework does not claim completeness and many effects are related to each other. However, the framework is a useful basis for designing evaluation studies and provides arguments in favour of at-stop real-time information displays.

  • 26.
    Dziekan, Katrin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Scholz, Agnes
    How to Measure “Ease-of-Use” in Public Transportation?: Scale construction and testing2008In: Umweltpsychologie, ISSN 1434-3304Article in journal (Other academic)
  • 27.
    Dziekan, Katrin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics, Traffic and Logistics.
    Sedin, S.
    Customer reactions to implementation of a trunk bus network in Stockholm/Sweden2005In: Proceedings of UITP Conference 2005 in Rome/Italy, 2005Conference paper (Refereed)
  • 28.
    Dziekan, Katrin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics, Traffic and Logistics.
    Vermeulen, Arjan
    Psychological effects of and design preferences for real-time information displays2006In: Journal of Public Transportation, ISSN 1077-291X, Vol. 9, no 1, p. 1-19Article in journal (Refereed)
    Abstract [en]

    This article investigates the effects of real-time information, located at stops and stations, on the public transportation customer. Perceived wait time, feelings of security, and ease of use were considered to be sensitive indicators. The case of newly implemented traveler information on tramline 15 in the Hague, the Netherlands, was used for a before-and-after evaluation study containing questionnaires given to travelers. One month before and 3 months and 16 months after implementation, the same sample of travelers completed in a questionnaire. Further, four orientations of the displays at tram stops, assembled for testing purposes, were evaluated. The main results were that the perceived wait time decreased by 20 percent, while no effects on perceived security and ease of use were found. Displays installed perpendicular to the tracks and separate from the shelter were ranked highest.

  • 29.
    Farah, Haneen
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Toledo, Tomer
    Passing behavior on two-lane highways2010In: Transportation Research Part F: Traffic Psychology and Behaviour, ISSN 1369-8478, E-ISSN 1873-5517, Vol. 13, no 6, p. 355-364Article in journal (Refereed)
    Abstract [en]

    Two-lane highways make up a substantial proportion of the road network in most of the world. Passing is among the most significant driving behaviors on two-lane highways. It substantially impacts the highway performance. Despite the importance of the problem, few studies attempted to model passing behavior. In this research, a model that attempts to capture both drivers' desire to pass and their gap acceptance decisions to complete a desired passing maneuver is developed and estimated using data on passing maneuvers collected with a driving simulator. Sixteen different scenarios were used in the experiment in order to capture the impact of factors related to the various vehicles involved, the road geometry and the driver characteristics in the model. A passing behavior model is developed that includes choices in two levels: the desire to pass and the decision whether or not to accept an available passing gap. The probability to complete a passing maneuver is modeled as the product of the probabilities of a positive decision on both these choices. The estimation results show that modeling the drivers' desire to pass the vehicle in front has a statistically significant contribution in explaining their passing behavior. The two sub-models incorporate variables that capture the impact of the attributes of the specific passing gap that the driver evaluates and the relevant vehicles, the geometric characteristics of the road section and the driver characteristics and account for unobserved heterogeneity in the driver population.

  • 30.
    Fröidh, Oskar
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Anläggningskostnader för järnvägar i Sverige 1989-20092009Report (Other academic)
  • 31.
    Fröidh, Oskar
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Modelling operational costs of a future high-speed train2006In: Conference proceedings to CIT 2006 conference, 2006Conference paper (Refereed)
    Abstract [en]

    In the Swedish Green Train research project, a model for calculation of operational costs has been developed. The model is intended as a tool for making a new high-speed train concept efficient and economically feasible. Some results indicate that seating density, i.e. the number of seats per metre of train length, is one of the most important factors to achieve economic train operation. The load factor needs to be high. However, to select service and comfort levels and other supply factors, travel demand and passengers’ willingness to pay also need to be considered.

  • 32.
    Fröidh, Oskar
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Jansson, Torleif
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Kapacitetsanalys av två principutfomningar av bansystemet på Ostlänken2005Report (Other academic)
  • 33.
    Fröidh, Oskar
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Kottenhoff, Karl
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Resandet längs Blekinge kustbana före, under och efter elektrifieringen2009Report (Other academic)
  • 34.
    Fröidh, Oskar
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Lindfeldt, Olov
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Svealandsbanans första 10 år: erfarenheter för framtiden av tågtrafiken och resandet2008Report (Other academic)
  • 35.
    Fröidh, Oskar
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Nelldal, Bo-Lennart
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Tåget till framtiden: järnvägen 200 år 20562008Report (Other academic)
  • 36.
    Huang, Zhen
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Ma, Xiaoliang
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Integration of Emission and Fuel Consumption Computing with Traffic Simulation using a Distributed Framework2009In: 2009 12TH INTERNATIONAL IEEE CONFERENCE ON INTELLIGENT TRANSPORTATION SYSTEMS (ITSC 2009), NEW YORK: IEEE , 2009, p. 154-159Conference paper (Refereed)
    Abstract [en]

    Air quality and fuel efficiency has become important factors in decision-makings on urban traffic planning and management. To support the process simulation models have potential to play essential roles in evaluation of planning alternatives and control strategies. However, traffic and its environmental impacts are different processes and often require various levels of models. With concerns on high computing performance and rich functionalities, it may be not appropriate to model emission inventory within traffic simulation. In this paper, we present a distributed simulation approach, and an independent emission/energy computing platform is built to simulate, visualize and analyze online emission outputs, given a microscopic traffic simulation tool, KTH-TPMA. Two distributed computing frameworks, common objects request broker architecture (CORBA) and service oriented architecture (SOA), are adopted in the distributed software design and implementation. Several emission models are implemented and generally evaluated in microsimulation runs of two road networks.

  • 37.
    Jansson, Kjell
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Pyddoke, R.
    Quality incentives and quality outcomes in procured public transport - Case study Stockholm2010In: Research in Transportation Economics, ISSN 0739-8859, E-ISSN 1875-7979, Vol. 29, no 1, p. 11-18Article in journal (Refereed)
    Abstract [en]

    Gross contracts appear to be the most common contract form for procured public transport in Sweden and elsewhere. This contract form, it has been argued, gives weak incentives for operators to deliver the desired quality level. Therefore many procuring public transport authorities amend contracts with quality incentives.This paper examines how such quality incentives influence quality outcomes with focus on cancelled departures and delays. The main findings are that the introduction of quality incentives are correlated with both increases and decreases of measured quality outcomes.We hypothesise that the results are driven by underlying cost changes for achieving desired quality objectives that exceed the possible revenues from the incentives. In interviews with the Stockholm public transport authority (SL) and some operators, two central observations surface. The first is that there are causes for quality failures that are not solely the responsibility of operators and that these are therefore not fully reached by the incentives, and the second is that the operators believe that they have exhausted what they can do under the current contracts.

  • 38.
    Kottenhoff, Karl
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Travel Increase and variation during bus and train periods2010Conference paper (Refereed)
  • 39.
    Kottenhoff, Karl
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Byström, Camilla
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    När resenärerna själva får välja2010Conference paper (Refereed)
  • 40.
    Kottenhoff, Karl
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Byström, Camilla
    När resenärerna själva får välja: sammanställning av attityder, perceptioner och värderingar2010Report (Other academic)
  • 41.
    Kottenhoff, Karl
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics, Traffic and Logistics.
    Freij, Karin Brundell
    The role of public transport for feasibility and acceptability of congestion charging - The case of Stockholm2009In: Transportation Research Part A: Policy and Practice, ISSN 0965-8564, E-ISSN 1879-2375, Vol. 43, no 3, p. 297-305Article in journal (Refereed)
    Abstract [en]

    In the Stockholm Trial, congestion charges and the expansion of public transport services were closely linked together in marketing efforts, as well as in political decisions. In this paper, we analyse the role that public transport may have played in increasing acceptability and feasibility of the scheme. We study four aspects of the relationship between charging and public transport provision: (i) the initial modal share, (ii) contribution to modal shift (iii) compensation to losers (iv) revenue hypothecation. Our analyses, based on a combination of primary and secondary data, support the hypothesis that public transport contributed to the successful implementation of congestion charging in Stockholm through all those four mechanisms.

  • 42. Larsson, Pia
    et al.
    Sochor, Jana
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301).
    Udin, Christian
    Sjöström, Thomas
    Jarlebring, Isak
    ITS and Telematic Services: Different Implementation Aspects2010Report (Other academic)
  • 43.
    Lindfeldt, Anders
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    A study of the performance and utilization of the Swedish railway network2010In: Road and Rail Infrastructure / [ed] Stjepan Lakušić, University of Zagreb , 2010Conference paper (Refereed)
    Abstract [en]

    Many lines in the Swedish railway network are heavily utilized and the demand forfreight transport and passenger traffic is increasing. The Swedish National RailAdministration has been forced to declare some sections to be overloaded andwith the up-coming deregulation of railway traffic, the load is going to increaseeven more.This paper describes how the performance of the entire Swedish railway networkhas been investigated and the results. Data from several different databases(supplied by the Swedish Railway Administration) has been processed. The dataconsists of the scheduled timetable, data about the design of the infrastructureand operational data such as recorded delays, train weights and train lengths.To perform the calculations, the railway network has been divided into 123sections. The division has been made according to traffic patterns and type ofinfrastructure (single-track, double-track). For each line, the data has been usedto calculate several descriptive parameters, e.g. delay development, number oftrains/h during different parts of the day, time for the peak hour, inter-stationdistance, track length, train length, train weight, total mass/day (freight trains),train average speed and the heterogeneity of the train speeds.Together, all of the parameters form a picture of the traffic flows in the Swedishrailway grid and identifies the characteristics of the different lines such as: load,traffic mix, delay situation and infrastructure performance. The information can beused to detect deficiencies and propose possible solutions.Finally, the correlation between the calculated parameters and the delay situationhas been investigated.

  • 44.
    Lindfeldt, Anders
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Congested railways: influence of infrastructure and timetable properties on delay propagation2012Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis the symptoms and underlying behaviour of congestion on railways are analysed and discussed. As well as in many other countries, Sweden faces increasing demand for transport. To meet this new demand, railways play an important role. Today, the capacity of the Swedish rail network is not upgraded at the speed necessary to keep up with the increase in traffic demand. The sensitivity of the railway system rises as the capacity utilisation increases. At some point the marginal gain of operating one extra train is lower than the costs in term of increased sensitivity to delay, i.e. maximum capacity has been reached.

    Two methodologies are employed in this thesis to analyse capacity. The first uses real data from the Swedish rail network, train operation and delays to analyse how different factors influence available capacity and delay creation. Several useful key performance indicators are defined to describe capacity influencing properties of the infrastructure and the rail traffic. The rail network is divided into subsections for which the indicators have been estimated. This makes it possible to discern their different characteristics and identify potential weaknesses.

     The second approach employs the railway simulation tool RailSys in extensive simulation experiments. This methodology is used to analyse the characteristics of double track operation. Simulation of several hundred scenarios are conducted to analyse the influence of traffic density, timetable speed heterogeneity, primary delays and inter-station distance on secondary delays and used timetable allowance. The analysis gives an in-depth understanding of the mechanisms behind the performance of a double track.

  • 45.
    Lindfeldt, Anders
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Kapacitetsanalys av järnvägsnätet i Sverige: Delrapport 2, Bearbetning av databas över infrastruktur, trafik, tidtabell och förseningar2009Report (Other academic)
  • 46.
    Lindfeldt, Olov
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Analysis of capacity on double-track railway lines2010In: Transportation planning and technology (Print), ISSN 0308-1060, E-ISSN 1029-0354Article in journal (Refereed)
    Abstract [en]

    In Sweden rail traffic is almost never separated according to speed. On several double-track lines the mix of heavy freight, regional and high speed trains imposes severe capacity problems. In order to evaluate the capacity for different traffic mixes a combinatorial model, TVEM (Timetable Variant Evaluation Model), has been developed. In this model both the infrastructure and the timetable are modelled as variables. The traffic is divided into train patterns according to a presumed regular timetable and then systematically scheduled in different time locations. The timetable variants are evaluated with regard to: mean values of capacity that give the number of trains/h for the required mix, variance measures that show how the capacity depends on the timetable and scheduled delays that show the extension of run times imposed by overtakings.

    The paper shows how the important distance between adjacent overtaking stations can be sampled from Weibull distributions. TVEM has been used to evaluate three different operational cases with mixed traffic. The analysis shows that the impact on capacity from the infrastructure increases with speed difference and frequency of operation for the passenger trains, while the importance of the infrastructure decreases when traffic is more homogeneous. The impact from the timetable is strongest when the speed differences are low and/or the frequency of passenger trains is low. Capacity loss due to increased speed differences can be compensated for with additional overtaking stations. The slower trains suffer from a considerable increase in scheduled delays when speed differences increase.

  • 47.
    Lindfeldt, Olov
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Crossing times on single-track railway lines: dependencies of different infrastructure and traffic factors2007In: Proceedings of Railway Engineering 9th International Conference and Exhibition / [ed] Ford, M.C., 2007Conference paper (Refereed)
    Abstract [en]

    Operation of single-track railway lines is characterised by crossings. Due to disturbances the crossing time is stochastic. Important properties such as capacity, run times and overall punctuality are strongly dependent on the crossing time. In non-congested situations the crossing time can be modelled analytically. SAMFOST (Simplified Analytical Model For Single Tracks) is a model that shows in a transparent way how the crossing time varies along a railway line.

    This paper shows how the mean crossing time function can be used to examine timetable flexibility, i.e. possibilities to change the timetable given constraints on the mean crossing time. Three different measures for timetable flexibility are proposed, showing how the available crossing points are spread along the line and the spread of mean crossing time for available crossing points.

    Many factors such as infrastructure parameters, vehicle parameters, timetable, delays etc affect the crossing time. In many cases these factors interact in complicated ways. To show this, the results of a 26-factorial experiment are presented. Partial double-tracks and passenger stops at timetable crossing points are examples of measures that give geographically local effects with strong interactions, whereas inter-station distance, vehicle type and arrival punctuality are factors with a more general impact and weaker interactions.

  • 48.
    Lindfeldt, Olov
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Effekter av partiella dubbelspår och fler mötesstationer på enkelspår2007Report (Refereed)
  • 49.
    Lindfeldt, Olov
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Evaluation of punctuality on a heavily utilised railway line with mixed traffic2008In: COMPUTERS IN RAILWAYS XI: COMPUTER SYSTEM DESIGN AND OPERATION IN THE RAILWAY AND OTHER TRANSIT SYSTEMS / [ed] Allan, J; Arias, E; Brebbia, CA; Goodman, C; Rumsey, AF; Sciutto, G; Tomii, N, 2008, Vol. 103, p. 545-553Conference paper (Refereed)
    Abstract [en]

    The Western Main Line (450 km) between Stockholm and Gothenburg is heavily utilised for mixed rail traffic. High speed trains are mixed with regional, local and freight trains and the congestion clearly affects the overall punctuality. In order to evaluate the possible total effects of reduced primary delays, the high speed operator, SJ AB, took the initiative to perform an extensive simulation study in RailSys, which was carried out by the Royal Institute of Technology. As preparation for this simulation study delay data was compiled for all trains using the line. This paper briefly discusses the ideas of stochastic disturbances in the simulation of rail operation and also the compilation methods for primary delay distributions. The resulting distributions from the Western Main Line were then analysed. It was clearly shown that the primary delays are extensive and have a high degree of variability. The paper ends with a discussion about the validation of the simulation model and possibilities to develop methods for more accurate stochastic modelling.

  • 50.
    Lindfeldt, Olov
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Impacts of infrastructure, timetable and perturbations in operation of double-track railway lines with mixed traffic2010In: 12th World Conference on Transportation Research 2010, 2010Conference paper (Refereed)
    Abstract [en]

    Delays play a central role in railway operation. They are of great importance both for customers and operators. They are direct measures of quality and reliability and hereby also an important factor for the competitiveness of the entire railway. Indirectly, the delays also affect quantitative factors such as capacity, i.e. the number of trains that can be (practically) operated. For these reasons, analysis of delays and delay propagation is an essential part of railway operations research.

    The up-coming deregulation of railway traffic means that completely mixed traffic can be foreseen on the Swedish railway network. This article shows how the delays on a double-track railway line, operated with mixed traffic, are affected by infrastructure, timetable and primary delays. Experimental design, simulation and response surface metamodelling are applied in a multi-factor simulation experiment with nine factors.

    The combination of simulation and experimental design makes it possible to draw general conclusions from a limited number of simulated variants and this type of multi-factor analysis is essential to an understanding of the railway as an operational system. The derived metamodels may also be used in different types of planning processes.

    The metamodels show that speed and frequency factors have a great impact on delays. Freight train speed and the frequency of service of high-speed trains in particular turned out to be important. Perturbation factors, i.e. entry delays, were found to affect the delays less. Neither does the distance between adjacent overtaking stations in itself affect the delays. However, the inter-station distance still affects delays through interactions with other factors.

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