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  • 351.
    Nelldal, Bo-Lennart
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Troche, Gerhard
    Jansson, Kjell
    Europakorridoren. Ett bredband för fysiska transporter. Utbud, prognoser och samhällsekonomi2003Report (Other academic)
  • 352.
    Nelldal, Bo-Lennart
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Troche, Gerhard
    Wajsman, Jakob
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Järnvägens möjligheter på den framtida godstransportmarknaden2000Report (Other academic)
  • 353.
    Nelldal, Bo-Lennart
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Troche, Gerhard
    Wajsman, Jakob
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    The prospects of freight by rail in the future transportation market2000Report (Other academic)
  • 354.
    Nelldal, Bo-Lennart
    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.
    Troche, Gerhard
    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.
    Wajsman, Jakob
    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.
    Sommar, Robert
    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.
    Linjetåg för småskalig kombitrafik: Analys av marknad och produktionssystem och förslag till pilotprojekt2011Report (Other academic)
  • 355.
    Nelldal, Bo-Lennart
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Wajsman, Jakob
    KTH.
    Godstransporter i Östra mellansverige 2010-2030-2050: En vision med prognoser för ett utvecklat transportsystem med järnväg2013Report (Other academic)
  • 356.
    Nelldal, Bo-Lennart
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Wajsman, Jakob
    Person- och godstransporter 2010-2030 och kapacitetsanalys för järnväg2011Report (Other academic)
  • 357.
    Nissan, Albania
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Koutsopoulos, Haris
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Evaluation of the Impact of Advisory Variable Speed Limits on Motorway Capacity and Level of Service2011In: 6TH INTERNATIONAL SYMPOSIUM ON HIGHWAY CAPACITY AND QUALITY OF SERVICE, Elsevier, 2011, p. 100-109Conference paper (Refereed)
    Abstract [en]

    Variable Speed Limits (VSL) have been introduced to improve the operations of freeway facilities under congested conditions. Experience indicates that the impacts of VSL on traffic performance and safety might be higher if the displayed speed limits were mandatory instead of recommended. This paper focuses on the impact of advisory VSL and proposes a statistical methodology for the comparison of traffic conditions before and after the implementation of VSL using the prevailing flow-density relationships. A case study, with data collected from the E4 motorway in Stockholm, is used to illustrate the methodology and evaluate the impact of advisory VSL. The results indicate that the advisory VSL had no significant impact on traffic conditions, both immediately after the implementation and several months later.

  • 358.
    Olofsson, Robert
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Freight value of time: An exploratory study for modelling freight.2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The main purpose of this project was to examine the reliability of Value of Time for freight

    applications by comparing the functionality of the Freight Value of Time modelling concept,

    with the functionality of the freight market.

    The research questions of this report are:

    How can the Freight Value of Time concept fulfil the requirements that decision

    makers in international freight have on the reliability of the modelling outcome?

    What are the differences between the multimodal and the unimodal applications of

    Value of Time in terms of validity?

    Within the scope of this study; modelling in the field of freight, logistics and supply chain

    management are presented with focus on Value of Time models. An overview of common

    freight models is initially presented as a starting point for literature reviews on

    trends and

    characteristics of the freight market

    , and on Freight Value of Time. These two literature

    reviews constitute the main methods of information retrieval on which the later analyses are

    based. The trends and characteristics of the freight market section provided the general

    requirements and a context for modelling freight, which was used for analysing and

    discussing Freight Value of Time.

    Additionally, a survey was performed in order to provide some insight into the requirements

    that analysts and decision makers have. The survey results were presented in the form of six

    examples of Swedish decision makers in freight. However, the survey results were deemed

    unsuitable for general conclusions due to a low response rate (6 out of 60).

    The analysis chapter of the report is divided into three parts; a

    general analysis section, a

    validity test of Freight Value of Time

    and a conceptual feasibility example. The general

    analysis focussed on issues with Freight Value of Time, the survey, freight market trends and

    multimodality.

    In the general analysis Global production networks and supply chains were identified as major

    trends and were used as the main modelling context when analysing Value of Time as a

    modelling concept for freight. The rest of the general analyses focuses on how well the

    modelling concept Value of Time corresponds to the functionality of the market.

    The validity test section showed that there are some possible issues with Freight Value of

    Time and that they can possibly be attributed to poor data availability and high aggregation

    levels.

    Therefore, the feasibility example study was performed for a conceptual case where data that

    is often missing was available. The specific data was characterised as supply chain data,

    which could be available to external analysts if the companies decide to share it. The

    feasibility study thereby tested if it actually was the lack of data that is the main reason for

    models including Freight Value of Time to lack validity according to the validity test. Access

    to data was found to be an important factor when creating a freight model with Value of

    Time, because by adding the supply chain data the performance of Freight Value of Time in

    the validity test was improved. However there were still potential issues with using Freight

    Value of Time concerning testing and verification in relation to the complexity of large scale

    freight models and the complexity of multimodal freight transport.

    The main issues with Value of Time identified throughout the project were:

    1. Discrete choice model selection

    2. High aggregation levels due to lack of data

    3. Explanatory variables

    4. Identification of decision makers

    5. Transport flow heterogeneity

    A set of four recommendations for analysts were devised from the hypothesis of:

    Models using Freight Value of Time are not reliable enough to be used in practise.

    The recommendations to analysts interested in Freight Value of Time were:

    -

    The specific model should be verified and validated before being used, which is

    probably best done for the specific application with a standardised verification and

    validation method such as the VV&A (used by Department of Defense in the USA).

    -

    Freight Value of Time is best used for unimodal applications, but for multimodal

    applications it could be reliable enough if the model is properly adapted to the

    complexity of the reality which is modelled.

    -

    The higher the complexity of a modelling scenario, the more data is needed. Therefore

    an analyst needs to make sure that this trade-off is kept at a level where the results fit

    the requirements of the application.

    -

    Low aggregation levels benefits the accuracy of the model, but increase the amount of

    calculations. It is therefore good to be aware of the risk of calculation errors.

    Summarised, the report concludes that Value of Time is sometimes the best method at hand

    but difficulties in gathering data can affect the accuracy negatively. Furthermore the

    complexity of multimodal freight transportation makes Value of Time less valid than for

    unimodal freight.

  • 359.
    Olofsson, Robert
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Gångpassager på spårväg: En trafiksäkerhetsstudie2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

     

    Syftet med detta kandidatexamensarbete var att undersöka hur utformningen av gångpassager på spårväg påverkar olycksrisken för fotgängare. En inventering av faktorer som påverkar planeringen av gångpassager, skyddsanordningar och statistik har gjorts för att skapa en överblick över utformningen av gångpassager på spårväg.

    För att bedöma hur trafiksäkra olika typer av utformningar är, har fallstudier utförts i Stockholm, Göteborg och Norrköping där fotgängarna som passerade på gångpassagerna studerades. Under fallstudierna noterades allvarliga konflikter mellan fotgängare och spårvagnar samt riskfyllda beteenden från fotgängarnas sida.

    I studien påvisas att det finns ett samband mellan utformningen av en gångpassage och olycksrisken. Det verkade dock inte vara så att det fanns typutformningar som alltid är mer trafiksäkra än andra utformningar.

    De faktorer som också visade sig ha inverkan på risken att en olycka inträffar var sikten, vilken typ av plats det är, trafiksituationen i övrigt och uppmärksamheten hos fotgängarna. Därför är det viktigt att försöka skapa uppmärksamhet och ta hänsyn till hur den specifika platsen ser ut vid utformning av gångpassager på spårväg.

    Av de studerade platserna var det en undersökt Shared Space lösning i Norrköping som bedömdes vara den mest trafiksäkra platsen därför att den var utformad på fotgängarnas villkor. En oreglerad gångpassage i Göteborg visade sig vara minst trafiksäker då detta var en plats med en komplex spårsituation, dålig sikt för fotgängarna och hög hastighet för inkommande spårvagnar.

    Metodiken som användes för att studera trafiken på gångpassagerna baserades på den "svenska konflikttekniken". Vidareutveckling av metodiken har gjorts fö

    r att kunna användas för spårvägar och för kortare observationsperioder.

  • 360. Ortt, Roland
    et al.
    Meijer, Sebastiaan
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Trevino Barbosa, Sandra
    Sequences of market niches prior to large-scale diffusion.2012In: Proceedings of IAMOT 2012, Taiwan, 2012Conference paper (Refereed)
  • 361. Osorio, Carolina
    et al.
    Flötteröd, Gunnar
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Analytical approximation of joint queue-length distributions of a finite capacity queueing network2013Conference paper (Refereed)
  • 362.
    Osorio, Carolina
    et al.
    Massachusetts Institute of Technology.
    Flötteröd, Gunnar
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Capturing dependency among link boundaries in a stochastic network loading model2012Conference paper (Refereed)
  • 363.
    Osorio, Carolina
    et al.
    mit.
    Flötteröd, Gunnar
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Capturing dependency among link boundaries in a stochastic network loading model2012Conference paper (Refereed)
  • 364. Osorio, Carolina
    et al.
    Flötteröd, Gunnar
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Capturing queue dependency in an analytical stochastic network loading model2012In: Proceedings of the Annual Meeting of the Transportation Research Board, Washington DC, USA, 2012Conference paper (Refereed)
  • 365.
    Osorio, Carolina
    et al.
    MIT.
    Flötteröd, Gunnar
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Bierlaire, Michel
    Dynamic network loading: a differentiable model that derives link state distributions2011In: Papers selected for the 19th International Symposium on Transportation and Traffic Theory / [ed] Cassidy, MJ; Skabardonis, A, Elsevier, 2011, p. 364-381Conference paper (Other academic)
    Abstract [en]

    We present a dynamic network loading model that yields queue length distributions, accounts for spillbacks, and maintains a differentiable mapping from the dynamic demand on the dynamic queue lengths. The model also captures the spatial correlation of all queues adjacent to a node, and derives their joint distribution. The approach builds upon an existing stationary queueing network model that is based on finite capacity queueing theory. The original model is specified in terms of a set of differentiable equations, which in the new model are carried over to a set of equally smooth difference equations. The physical correctness of the new model is experimentally confirmed in several congestion regimes. A comparison with results predicted by the kinematic wave model (KWM) shows that the new model correctly represents the dynamic build-up, spillback, and dissipation of queues. It goes beyond the KWM in that it captures queue lengths and spillbacks probabilistically, which allows for a richer analysis than the deterministic predictions of the KWM. The new model also generates a plausible fundamental diagram, which demonstrates that it captures well the stationary flow/density relationships in both congested and uncongested conditions.

  • 366.
    Pettersson, Pierre
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Schmoecker, Jan-Dirk
    Active ageing in developing countries?: - trip generation and tour complexity of older people in Metro Manila2010In: Journal of Transport Geography, ISSN 0966-6923, E-ISSN 1873-1236, Vol. 18, no 5, p. 613-623Article in journal (Refereed)
    Abstract [en]

    There is by now quite a substantial body of literature discussing the impact of an ageing population in developed countries on travel needs and required changes to transport policy. As many newly developed and developing countries are following demographic trends of "first world" countries, but offset by some decades, the problem is, however, not limited to the industrialised nations. The focus of this paper is on Metro Manila and analyses travel patterns by those aged 60 or over. Trip frequency and tour complexity are analysed with ordered probit regression, separating the effects of socio-demographic characteristics as well as land-use patterns. The results are compared to observations made for cities in developed countries, in particular London as an example for a city in a first world country. We show that there is a more pronounced decrease in total trips made with increasing age in Manila. However, analysing for specific trip purposes we find, similarly to trends in developed countries, that the number of recreational trips is fairly constant in all age groups. Recreational activities also seem to take more time per day than average for younger old, possibly indicating the advent of similar active ageing trends as in industrialised nations. The paper concludes by discussing some implications given future economic trends and advocates that better datasets from developing and newly developed countries are required for urban planning in developing countries.

  • 367.
    Psaraki-Kalouptsidi, Voula
    et al.
    National Technical University of Athens (NTUA).
    Pagoni, Ioanna
    National Technical University of Athens (NTUA).
    Fröidh, Oskar
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    TOSCA. Transport Infrastructure Capacity Assessment. Rail transport2011Report (Other academic)
    Abstract [en]

    The TOSCA project aims to identify promising technology and fuel pathways to reducetransportation-related greenhouse gas emissions through midcentury. An important buildingblock of this project is the techno-economic specification of low-GHG emission transportationtechnologies, which are input into a scenario analysis. TOSCA considers all major modes ofpassenger and freight transport, along with transportation fuels and technologies capable ofenhancing infrastructure capacity. This report is thus one out of a number of such technoeconomicstudies.In TOSCA Work Package 5 (WP5), technologies that could be implemented in European roadand rail infrastructure over the next 40 years are evaluated for both passenger and freighttraffic. In this deliverable (D6.3) technologies for rail transport are examined. Thesetechnologies refer to measures that could improve the existing infrastructure capacity andcould impact energy use and GHG emissions.First a reference system is defined including TEN-T high-speed railways primarily for passengeroperations and freight corridors. Then two railway technologies are assessed: the EuropeanRail Traffic Management System (ERTMS)-(ETCS/Level 3) and Heavier/Faster freight trains.Both are viewed as capacity-enhancing technologies, while the second technology can alsocontribute to GHG emissions reduction. The potential for capacity improvements by ERTMS(ETCS/Level 3) might be anything ranging from 15 to 60%, while the capacity of Heavier/Fasterfreight trains could be up to 200% higher than the reference system. Evidence suggests thatboth technologies require substantial research and are expected to enter the Europeanmarket during the next decades. Evaluation results are also presented in terms of the basicdimensions of technological feasibility, social acceptability and user acceptability.

  • 368.
    Qamhieh, Dima
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Intermodal Terminals Node-Place Issue and Travelers´ Flow: Case study: Gothenburg central station2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Intermodal terminals are complex entities; they are nodes in transport networks, and places in the city simultaneously; permanently or temporarily inhabited with compact and varied collection of uses and forms accumulated through time. The purpose of this thesis was to explore the complexities involved in the issue of smooth pedestrian flows within station areas. Gothenburg central station was selected as the empirical case study of this thesis, since it is a station area currently meeting big challenges in terms of smooth pedestrian flows. The thesis was carried out through a literature review for several topics relevant to the complexities of the pedestrian flows at intermodal terminals, such as the node-place dilemma, traveler’s characteristics, flows and the physical layout of stations, and an empirical analysis of the pedestrian flow in the station with specific focus on two bottlenecks within the main building. The empirical analysis was carried out by means of semi-structured interviews with representatives from some of the key institutions involved in the organization of the central station, together with field observations and video filming. The results of the thesis illustrate clearly the need for a more thorough reflection on what main function the railway station should fill today; and understand the node-place dilemma and its consequences for smooth pedestrian flow and accessibility for travelers moving in the station building. More specifically, the thesis recommends several services within the station building to be re-arranged so it guarantees a smoother flow for travelers now and in the future. In addition, it calls for special attention toward elderly and special needs travelers and the importance to address their status in the station within all stakeholders’ development schemes.

  • 369.
    Radano, Francesco
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Orth, Hermann
    Schmidt, Philipp
    Intermodal Solutions for Trans-European Temperature-Sensitive Shipments, TESS WP4 report2011Report (Other academic)
  • 370.
    Raghothama, Jayanth
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Meijer, Sebastiaan A.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    A review of gaming simulation in transportation2014In: Frontiers in Gaming Simulation: 44th International Simulation and Gaming Association Conference, ISAGA 2013 and 17th IFIP WG 5.7 Workshop on Experimental Interactive Learning in Industrial Management, Stockholm, Sweden, June 24-28, 2013. Revised Selected Papers, Springer, 2014, p. 237-244Conference paper (Refereed)
    Abstract [en]

    Gaming simulation has proven to be an invaluable method for experimentation and learning and exploring scenarios in various fields of policy making. In this paper, we present a case for the use of gaming simulation in transportation analysis. We also present a review of games and gaming simulation in transportation analysis. We observe that gaming simulation is not widely used in transportation, despite its wide use in associated fields.

  • 371.
    Rahimi, Sepehr
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Improving Tram Speed: A case study of proposed tramline ODENPLAN-SOLNA2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In 2010,  an  inner  city tramline (Sparvag City linje  7) was  introduced in Stockholmcity connecting the Central  Square, Sergei torgs  to Djurgarden, an island  southeast of the  city center. This was the first  inner city tram since 1967. Odenplan-Solna is now being  investigated as a second inner city tram.  The traffic situation shows that  even today's traffic  cannot cope  with  the  existing public  transport facilities.  In order to have  reliable, high  quality and  high  frequency tramline in  this  area,  speed is  an important issue.  This study is an attempt to put forward suggestions to improve the speed  of  the   suggested  tramline  Odenplan-Solna through  a  review  of  different operating trams in several cities;  including newly  introduced and  established ones. Due to time limitation, it has been  decided  to pick some  interesting cities to serve  as benchmarks. The  literature review helps  to  compare different tram's speed to  see what could   be  the   expected  average  speed  of  the   Odenplan-Solna  tramline.  In previous work  by Sweco the network of Oden plan -Solna was simulated using Vissim. The   model   results  show  the   average  speed  far  below   the   target  of  20   km/h considering different factors that  affect  tram's speed, e.g. number of stops, distance between stations, boarding and  alighting passengers, etc. Through the  survey from several cities and the  Filmad Framkomlighet experiment, the target for this study has been  changed to  16  kmjh. Several  scenarios have  been  tested using  Vissim.  The results show improvements in some  tramlines, though the average tram speed is still below  16.  Results  from  tested scenarios show  tram  traffic  is difficult  to  achieve  in this corridor and significant changes have to be considered to improve overall speed.

  • 372.
    Rahmani, Mahmood
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Path Inference of Sparse GPS Probes for Urban Networks: Methods and Applications2012Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The application of GPS probes in traffic management is growing rapidly as the required data collection infrastructure is increasingly in place in urban areas with significant number of mobile sensors moving around covering expansive areas of the road network. Most travelers carry with them at least one device with a built-in GPS receiver. Furthermore, vehicles are becoming more and more location aware. Currently, systems that collect floating car data are designed to transmit the data in a limited form and relatively infrequently due to the cost of data transmission. That means the reported locations of vehicles are far apart in time and space. In order to extract traffic information from the data, it first needs to be matched to the underlying digital road network. Matching such sparse data to the network, especially in dense urban, area is challenging.

    This thesis introduces a map-matching and path inference algorithm for sparse GPS probes in urban networks. The method is utilized in a case study in Stockholm and showed robustness and high accuracy compared to a number of other methods in the literature. The method is used to process floating car data from 1500 taxis in Stockholm City. The taxi data had been ignored because of its low frequency and minimal information. The proposed method showed that the data can be processed and transformed into information that is suitable for traffic studies.

    The thesis implemented the main components of an experimental ITS laboratory, called iMobility Lab. It is designed to explore GPS and other emerging traffic and traffic-related data for traffic monitoring and control.

  • 373.
    Rahmani, Mahmood
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Jenelius, Erik
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS. KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics. KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis.
    Koutsopoulos, Haris
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Route travel time estimation using low-frequency floating car data2013Conference paper (Refereed)
  • 374.
    Rahmani, Mahmood
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Jenelius, Erik
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS. KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics. KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis.
    Koutsopoulos, Haris
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Route travel time estimation using low-frequency floating car data2013In: 2013 16th International IEEE Conference on Intelligent Transportation Systems - (ITSC): Intelligent Transportation Systems for All Modes, IEEE conference proceedings, 2013, p. 2292-2297Conference paper (Refereed)
    Abstract [en]

    The paper develops a non-parametric method for route travel time estimation using low-frequency floating car data (FCD). While most previous work has focused on link travel time estimation, the method uses FCD observations directly for estimating the travel time distribution on a defined route. A list of potential biases associated with FCD is presented and discussed. For each source of bias, a correction method for the observations is proposed. The estimation method is implemented using FCD data from taxis in Stockholm, Sweden. Estimates are compared to observed travel times for two routes equipped with automatic number plate recognition (ANPR) cameras. The mean travel time estimates incorporating all bias corrections perform equally well or better than the link-based approach in terms of RMSE, and estimated percentiles show a good match to ANPR.

  • 375.
    Rahmani, Mahmood
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Koutsopoulos, Hans N.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Path inference from sparse floating car data for urban networks2013In: Transportation Research Part C: Emerging Technologies, ISSN 0968-090X, E-ISSN 1879-2359, Vol. 30, p. 41-54Article in journal (Refereed)
    Abstract [en]

    The use of probe vehicles in traffic management is growing rapidly. The reason is that the required data collection infrastructure is increasingly in place in urban areas with a significant number of mobile sensors constantly moving and covering expansive areas of the road network. In many cases, the data is sparse in time and location and includes only geo-location and timestamp. Extracting paths taken by the vehicles from such sparse data is an important step towards travel time estimation and is referred to as the map-matching and path inference problem. This paper introduces a path inference method for low-frequency floating car data, assesses its performance, and compares it to recent methods using a set of ground truth data.

  • 376.
    Rahmani, Mahmood
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Koutsopoulos, Haris
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Path inference of low-frequency GPS probes for urban networks2012In: Intelligent Transportation Systems (ITSC), 2012 15th International IEEE Conference on, IEEE , 2012, p. 1698-1701Conference paper (Refereed)
    Abstract [en]

    The use of probe vehicles in traffic management is growing rapidly. The reason is that the required data collection infrastructure is increasingly in place in urban areas with significant number of mobile sensors moving around covering expansive areas of the road network. The data is usually sparse in time and location. It usually includes only geo-location and timestamp. Extracting the paths taken by the vehicles is an important step in using this data. Such methods are referred to as map-matching or path inference. This paper introduces a path inference method for low-frequency probes and evaluates its accuracy in comparison to a recent method.

  • 377.
    Robles, Danny
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Optimal signal control with multiple objectives in traffic mobility and environmental impacts2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The increasing number of motor vehicles in urban areas worldwide requires a smart traffic management establishing sustainability on the traffic system. Traffic signal control is a powerful tool in this field since it can control flow patterns in urban areas. Historically, traffic signal optimization was applied to satisfy the goals in mobility of traffic systems e.g. measured by travel delay, stops etc., and very little is known if such a strategy would be optimal for system sustainability in terms of emission and fuel usage. The thesis focus on finding the trade-offs between mobility and impact measures and compares these with approximated real signal strategies.

    The research objective of the thesis is to create a multi-objective computa- tional framework based on the integration of a microscopic traffic simulation model with a micro scale fuel and emission model. The proposed framework is able to implement mobility and impact objectives in a multi-objective opti- mization process. The microscopic traffic model VISSIM is used to simulate the traffic and two different emission models, CMEM and VT-Micro, are used to estimate the vehicular emissions and fuel consumption. The optimization

    is based on NSGA

    ii, a multi-objective genetic algorithm.

    The proposed framework is demonstrated by conducting two case studies, a single intersection in Wuhan and two coordinated intersections in Stockholm. The investigated objectives used in the optimizations are network delay, av- erage number of stops and average fuel consumption. Moreover, the best solution of each objective is subjected to a emission evaluation. Due to time consuming optimization processes, an upper limit of iterations is set for both cases. All simulations are based on 60 minutes of traffic simulations with additional 15 minutes for warm up.

    The study shows that the proposed framework is successful in finding signal control strategies producing better values of the investigated objectives com- pared to the real signal approximations. One could also see apparent trade-off between mobility and sustainability depending on the selected objectives.

  • 378.
    Rommel, Jacob
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Höghastighetståg - Är det framtiden?2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 379.
    Rondon, Abraham
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    The impact of weather conditions on urban travel speed using ANPR observations.2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Weather conditions may impact traffic flow in different ways. Both the human decisions

    regarding the trip (route, mode, time) and the trip itself can significantly vary.

    Driver’s

    behavior may be affected by weather resulting in, among others, deterioration of the

    network

    ’s travel times and speeds.

    Therefore to study and analyse travel times under different weather conditions, represents an

    important instrument to support Intelligent Transport Systems (ITS). With the correct

    knowledge and information, travellers would be able to plan their trips in a cost-efficient way,

    while traffic managers could take advantages of these predictions to deploy control strategies

    (e.g. weather-responsive signal timing plans).

    In this project Automatic Number Plate Recognition (ANPR) data from summer 2012 to

    summer 2013 from three different arterial routes in Stockholm city is used in order to analyze

    travel times, at a link level, under different weather conditions.

    To determine to what extent weather variables such as rain, snowfall, temperature and

    visibility impact the speeds in the network, weather data is integrated with traffic data

    (ANPR) and analyzed through linear regression models.

    Results show that there is in fact a negative effect on speed but also on

    speed’s variability.

    This knowledge can be useful for trip planning and for traffic management under different

    weather conditions.

     

  • 380.
    Sarlas, Georgios
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Processing low-frequency floating cardata for transportation applications.2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 381.
    Schmidt, Lotta
    et al.
    WSP.
    Kottenhoff, Karl
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    När resenärerna själva får välja2012Conference paper (Refereed)
  • 382. Sehic, E.
    et al.
    Verbraeck, A.
    Meijer, Sebastiaan A.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    A game for requirements formulation for a distributed gaming and simulation environment2014In: Frontiers in Gaming Simulation: 44th International Simulation and Gaming Association Conference, ISAGA 2013 and 17th IFIP WG 5.7 Workshop on Experimental Interactive Learning in Industrial Management, Stockholm, Sweden, June 24-28, 2013. Revised Selected Papers, Springer, 2014, p. 129-139Conference paper (Refereed)
    Abstract [en]

    ProRail is the owner of a number of high fidelity train traffic simulators for designing and managing the physical rail infrastructure. Gaming simulation is used to support the analysis and redesign of rail management and control processes. The games should use the existing train traffic simulators as much as possible to reduce costs and keep the existing knowledge base and acceptance. Because of their high fidelity level, these simulators lack the more abstract level that is necessary for interaction with humans in a gaming setting. Therefore they need to be adjusted. As there are several simulators to be used and multiple disciplines involved, this is not a trivial task. On the basis of the played Early Decision at Disruptions Game it is examined what requirements need to be fulfilled to make ProRail simulators suitable for use in gaming, in order to maximize profits of the coupling between simulators and games. This paper describes the process followed and provides a refined set of requirements for coupling of simulators for use in management and control games in rail (physical) infrastructures.

  • 383.
    Silvano, Ary
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Bång, Karl-Lennat
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    The impact of speed limits and road characteristics ondrivers’ free-flow speed in urban areasManuscript (preprint) (Other academic)
  • 384.
    Silvano, Ary
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Farah, Haneen
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Koutsopoulos, Harilaos N.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Simulation-based evaluation of theimpact of I2V systems on traffic performanceManuscript (preprint) (Other academic)
  • 385.
    Silvano, Ary
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Farah, Haneen
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Koutsopoulos, Harilaos N.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    The free-flow speed distributionon urban roads: A probabilistic approach to model time headway thresholdsManuscript (preprint) (Other academic)
  • 386.
    Silvano, Ary P.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Impacts of Speed Limits and Information Systems on Speed Choice from a Safety Perspective.2013Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Driving a vehicle is considered a demanding task in a complex dynamic environment. For instance, driving a vehicle on urban roads, where motorized vehicles meet vulnerable road users (VRUs) creates a multifaceted environment with difficult trade-offs and interactions. Additionally, in-vehicle technology developments are being introduced to ease drivers with the driving task. However, these developments are changing “traditional” driving increasing drivers’ response in terms of information processing, thus making the driving task more demanding in some respects. Therefore, the aim of the present research is to further investigate drivers’ speed choice under varying traffic management regulations and in-vehicle warning systems.  

  • 387.
    Sipilä, Hans
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Calibration of Simulation Model on the Southern Main Line in Sweden2011Conference paper (Refereed)
    Abstract [en]

    Suitable analysis methods are needed for evaluation of future timetable scenarios, both in short term operational planning and for strategic planning with a longer time horizon. One method is to use simulation software which makes it possible to model large networks. The Swedish Transport Administration (Trafikverket) is in a process where the aim is to start using simulation software RailSys as a tool for timetable planning. This will at first be applied for long term strategic planning with the possibility to also use it in operational planning further on.

    The main focus in this paper is to estimate primary run time extensions from registered data. Ideally these should only represent primary causes, e.g. decreased vehicle performance, variation in driver behaviour or infrastructure malfunctions. These extensions are important in order to make simulations more realistic.

    Different reduction levels of registered data are tested in order to estimate primary run time extensions. Registered data used are absolute values without distinction between primary and secondary causes. Calibration simulations are done on the Southern main line in Sweden where the mix of high and low speed trains is substantial.

  • 388.
    Sipilä, Hans
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Simulation of rail traffic: applications with timetable construction and delay modelling2012Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis covers both applications where simulation is used on parts of the Swedish rail networks and running time calculations for future high-speed trains with top speed improvements on existing lines. Calculations are part of a subproject within the Green Train research program (Gröna tåget). Higher speeds are possible with increased cant and cant deficiency in curves. Data for circular curve radii is used on existing lines combined with information on decided and on-going upgrades. Calculation of static speed profiles is made for a set of cant and cant deficiency values. Different train characteristics are used regarding top speed, starting acceleration and power to ton ratio. Running time calculations are made for these different train characteristics with the fictive speed profiles. In addition, different stopping patterns are applied. Results are presented together with running times for two reference train types, one with carbody tilting and one without. It is clear that carbody tilting, allowing a higher cant deficiency, is important on many of the existing lines considering achieved running times. The benefit of tilting is marginal on newly built and future lines designed with large curve radii. However, on many of the existing lines the over 20 year old reference train with carbody tilting achieves shorter running times compared to a future train without tilt but with higher top speed. The work presented here has contributed with input to other projects and applications within the research program. Simulation in RailSys is used to evaluate on-time performance for high-speed trains, between Stockholm and Göteborg in Sweden, and changes in timetable allowances and buffer times with respect to other trains. Results show that ontime performance can be improved with increased allowances or buffer times. In the case with increased buffers, other trains are pushed in the timetable with the intention of obtaining at least five minutes at critical places (e.g. conflicting train paths at stations) and as separation on line sections. On-time performance is evaluated both on aggregated (group) level and for trains individually. Some of the trains benefit significantly from the applied measures. Prior to a simulation some of the delays have to be defined. This includes dwell extensions and entry delays, i.e. extended exchange times at stations and delayed origin station departures inside or at the network border. Evaluation of observed data give insight on the performance of a real network. However, separating primary (exogenous) and secondary (knock-on) delays is not straightforward. Typically the probabilities and levels of primary delays are defined as input, thus secondary delays are created in the simulations. Although some classification of delays exist in observed data, it is not sufficient without further assumptions and preparation. A method for estimating primary running time extensions is presented and applied on a real timetable between Katrineholm and Hässleholm in Sweden. The approach consist of creating distributions based on deviations from scheduled running time. Since this represent total outcome, i.e. both primary and knock-on delays are included, the distributions are reduced by a certain percentage and applied in the simulations. Reduction is done in four steps, separately for passenger and freight trains. Root mean square error (RMSE) is used for comparing mean and standard deviation values between simulated and observed data. Results show that a reasonably good fit can be obtained. Freight services show a higher variation than passenger train evaluation groups. Some explanations for this are difficulties in capturing the variations in train weights and speeds and absence of shunting operations in the model. In reality, freight trains can also frequently depart ahead of schedule and this effect is not captured in the simulations. However, focus is mostly on passenger trains and their on-time performance. If a good enough agreement and operational behaviour is achieved for them, a lower agreement for freight trains may be accepted.

  • 389.
    Sipilä, Hans
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Simuleringsmetoder i RailSys tillämpat på Södra stambanan2012Conference paper (Other academic)
  • 390.
    Sipilä, Hans
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Warg, Jennifer
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Kapacitetsanalys av Södra stambanan: Effekter av ökad trafik och ökad hastighet från 200 till 250 km/h2012Report (Other academic)
  • 391.
    Sjögren, Marieann
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Klimatsmart resande inom trafikverket - en djupstudie2012Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 392. Sjöström, Thomas
    et al.
    Sochor, Jana
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Larsson, Pia
    ITS and Telematic Services: Different Implementation Aspects2011Conference paper (Refereed)
  • 393.
    Snickars, Folke
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Mattsson, Lars-Göran
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics. KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    Olofsson, Bo
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering (moved 20130630), Environmental Physics.
    Sustainable urban flows and networks: Theoretical and practical aspects of infrastructure development and planning2013In: Sustainable Stockholm: Exploring Urban Sustainability in Europe's Greenest City / [ed] Jonathan Metzger, Rader Olsson Amy, Routledge, 2013, p. 102-128Chapter in book (Refereed)
  • 394.
    Sochor, Jana
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Impacts of Intelligent Transportation Systems on Users' Mobility:  A Case Study Analysis2012Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    People have many reasons to be mobile, from day-to-day activities involving work, studies, and family, to maintaining participation in society, health, and quality of life. Information and Communication Technology (ICT) is increasingly being deployed in the transportation context to improve individuals' mobility; for example via information provision. Advanced use of ICT in transportation is commonly referred to as Intelligent Transportation Systems (ITS).

    Despite many opportunities for ITS services to enhance personal mobility, the collection and use of movement and activity data also poses challenges, as it facilitates easier access to more information for people to use, but about them as well. Knowledge about users' perceptions of advantages and disadvantages (for example assurance and privacy) associated with the use of ITS services is limited. Even less is known regarding to what degree their perceptions influence their acceptance of the services or their behavior.

    The aim of this thesis project is to gather empirical interview and survey data from multiple user groups in order to learn more about the factors impacting users' attitudes towards ITS services. In exploring not only demographic factors, but also the potential positive and negative impacts from the users' perspective, this project attempts to paint a more holistic view of the issues surrounding the possibilities for ITS to enhance mobility.

    From the two case studies presented in this thesis, results indicate that respondents are pro-technology and are not highly concerned about privacy in general, but other ethical issues serve to shed light on the situations of different user groups. In the first case study with visually impaired individuals, the ability to lead an autonomous and independent life is a strong driver for the acceptance of a pedestrian navigation system, which the users themselves would choose to use. While the participants are generally optimistic about the possibilities of using ITS to enhance their mobility, their comments illustrate that ICT development does not necessarily result in ethically sound, universally accessible technology, and that a coordinated effort on multiple fronts is vital in addressing users' needs and meeting broader social goals such as social inclusion and the accessibility of transportation, technology, and information.

    In the second case study with professional heavy goods vehicle drivers and their employers, the drivers are in a dependent (employee) position and have less personal control over the use of ITS services in the vehicles. The employers are perceived as the greater beneficiaries of the services, which could be linked to the systematic lack of feedback to the drivers. Generally, the respondents trust the employers to protect the drivers' privacy. However, there also exist gaps in organizational communication regarding data gathering and handling practices as well as in expected versus stated behavior modification as a result of workplace monitoring. As employees are not normally able to provide informed consent due to their dependent position, recommendations for organizations include performing comprehensive impact assessments, engaging in an ongoing dialogue with employees, and providing an opt-out option in order to move towards a more informed consent.

  • 395.
    Sochor, Jana
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Older Adults' Attitudes Towards and Acceptance of ITS Systems2011Other (Other academic)
  • 396.
    Sochor, Jana
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Privacy in the Professional Driver’s Workplace2012In: 19th Intelligent Transport Systems World Congress, ITS 2012, Linköping, Sweden, 2012Conference paper (Refereed)
    Abstract [en]

    The aim of this paper is to provide a discussion about workplace privacy in the context of the professional HGV driver, as well as to empirically investigate the attitudes of the drivers and their employers regarding this issue. It explores privacy issues from an organizational and employee-employer perspective via three types of concerns: individuals' privacy rights, protection of personal information, and workplace surveillance, i.e. performance and behavioral monitoring. This study differs from earlier work on workplace privacy in that it specifically addresses the mobile HGV workplace, which is generally only briefly mentioned as a example of detailed, real-time workplace surveillance. The results (based on interviews with professional HGV drivers (employees) and road haulage company representatives (employers) in Sweden) do not indicate high levels of concern over privacy in general, protection of employees' personal information, or performance and behavioral monitoring. However, the interviews reveal a communication gap between drivers and companies regarding privacy policies and practices, and differences in perceptions of ITS services' benefits for the companies versus the drivers. Suggested methods to improve organizational communication and driver benefit include ongoing, two-way dialogue about ITS services, feedback mechanisms to raise behavioral awareness, and before-after studies to investigate possible behavioral impacts.

  • 397.
    Sochor, Jana
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    The Reassuring Affects of ICT in Public Transportation: The Perspectives of Older Adults2013In: Gerontechnology, ISSN 1569-1101Article in journal (Other academic)
    Abstract [en]

    In investigating older adults’ perspectives on ITS related to public transportation, the effect of personal control over ITS use is explored across three scenarios: video surveillance in public transportation, real-time travel information, and a personal, pedestrian navigation system with public transportation information. Swedish respondents’ perceptions indicate neutral effects on privacy and positive effects on one’s sense of assurance across the scenarios, particularly in situations perceived as more vulnerable, such as using the subway and traveling alone or in an unfamiliar setting.  Of the three technological applications, video surveillance (CCTV) elicits the most favorable responses, although this does not directly translate to perceived personal benefit, where real-time information is rated the highest. The navigation system is generally ranked relatively lower for effects on assurance, although this pattern is broken for car and walking modes; modes in which the navigation function may be prioritized.  Thus, personal control over aspects of the trip, rather than personal control over ITS use, better explains the responses, as ITS can serve to reduce (perceived) uncertainties, improving one’s sense of assurance.  Significant differences are found for gender, but not for further age stratification. Overall, female respondents feel relatively less assured when traveling and rate the technological applications’ effects on their assurance more highly than men. Although men express a greater personal interest in technology, it appears that there is more potential for women to positively benefit from technology in terms of greater perceived assurance while traveling.  This calls into question the possibilities of effectively addressing user needs or concerns, especially via technologies intended for individual use, if those who potentially serve to gain more by them are not being reached or are not as interested in such “solutions”.

  • 398.
    Sochor, Jana
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    User Acceptance and IT: Privacy Issues and Concerns When Enhancing Mobility2011Report (Other academic)
  • 399.
    Sochor, Jana
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    User Attitudes and Acceptance of ITS2011Other (Other academic)
  • 400.
    Sochor, Jana
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    User Attitudes and Acceptance of ITS Services2011Other (Other academic)
5678910 351 - 400 of 457
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