Change search
Refine search result
1 - 24 of 24
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Andreasson, Ingmar J.
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Extending PRT capabilities2009In: Automated People Movers 2009: Connecting People, Connecting Places, Connecting Modes: Proceedings of the twelfth international conference, May 31-June 3, 2009 : Atlanta, Georgia, American Society of Civil Engineers (ASCE), 2009, p. 343-349Conference paper (Refereed)
    Abstract [en]

    Personal Rapid Transit (PRT) offers direct, on-demand travel in automated vehicles seating 3-6 passengers on exclusive right-of-way. Commercially available systems now offer speeds up to 45 kph at headways from 3 seconds. With 3-second headways, a typical load of 1.5 passengers and 30 empty vehicles, the link capacity will be 1200 passengers per hour (one direction). This paper explores ways to extend the capabilities of PRT with respect to capacity and speed. Strategies have been developed and verified with the generic simulation software PRTsim.

  • 2.
    Andreasson, Ingmar J.
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Personal Rapid Transit as Feeder-Distributor to Rail2012In: Transportation Research Record, ISSN 0361-1981, E-ISSN 2169-4052, no 2275, p. 88-93Article in journal (Refereed)
    Abstract [en]

    Efficient feeder distributor systems around train stations are important in attracting train passengers. Such systems would be a suitable application for personal rapid transit (PRT). This paper suggests layouts and operations strategies for transfer stations between PRT and heavy rail. Ticket handling can be avoided by having the train fare include PRT trips. Ridesharing can be encouraged by destination signs. The catchment area that can be efficiently served is related to the interval between trains. The capacity of the station and guideway can be improved by coupling PRT vehicles in the station and decoupling them as necessary en route. Applications in Sweden are illustrated with the PRTsim software. In one case, outgoing PRT vehicles were loaded to 78%.

  • 3.
    Avery, Ryan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301). KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Burghout, Wilco
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301). KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Andréasson, Ingmar
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301). KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    An Interactive Tool for Collecting Traveler Behavior Information2008Conference paper (Refereed)
  • 4.
    Avery, Ryan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics.
    Burghout, Wilco
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics.
    Andréasson, Ingmar
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics.
    An Interactive Tool for Collecting Traveler Behavior Information2008In: Proceedings of the 87th Transportation Research Board Annual Meeting, Jan. 2008, 2008Conference paper (Refereed)
    Abstract [en]

    Understanding driver behavior and response to traffic information is necessary in order toachieve the maximum benefit from Advanced Traveler Information Systems (ATIS). This paperdescribes the development of a travel simulator to collect information on driver route choice inresponse to traffic information. A main feature of the simulator is the realistic representation ofmultiple traffic information sources (currently VMS and radio messages). Furthermore, thesimulator is one of the first Internet-based travel simulators, and the only one that accuratelysimulated the driving task. The simulator consists of collection of pre-trip information anddefault route information followed by multiple simulated trips with varying incidents and trafficinformation. The simulator is evaluated and measures well against established guidelines fortravel simulator development. Results will be discussed in future papers as data collection usingthe simulator is ongoing as of August 2007.

  • 5.
    Burghout, Wilco
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR. 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.
    Andreasson, Ingmar
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR. KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    A Discrete-Event Mesoscopic Traffic Simulation Model for Hybrid Traffic Simulation2006In: IEEE Intelligent Transportation Systems Conference, 2006. ITSC'06, IEEE , 2006, p. 1102-1107Conference paper (Refereed)
    Abstract [en]

    The paper presents a mesoscopic traffic simulation model, particularly suited for the development of integrated meso-micro traffic simulation models. The model combines a number of the recent advances in simulation modeling, such as discrete-event time resolution and combined queue-server and speed-density modeling, with a number of new features such as the ability to integrate with microscopic models to create hybrid traffic simulation. The ability to integrate with microscopic models extends the area of use to include evaluation of ITS systems, which often require the detailed modeling of vehicles in areas of interest, combined with a more general modeling of large surrounding areas to capture network effects of local phenomena. The paper discusses the structure of the model, presents a framework for integration with micro models, and illustrates its validity through a case study with a congested network north of Stockholm. It also compares its performance with a hybrid model applied to the same network.

  • 6.
    Burghout, Wilco
    et al.
    KTH, Superseded Departments, Infrastructure.
    Koutsopoulos, Haris
    Andreasson, Ingmar
    KTH, Superseded Departments, Infrastructure.
    Hybrid mesoscopic-microscopic traffic simulation2004Conference paper (Refereed)
  • 7.
    Burghout, Wilco
    et al.
    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 Traffic Research, CTR.
    Koutsopoulos, Haris
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Andreasson, Ingmar
    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 Traffic Research, CTR.
    Incident Management and Traffic Information: Tools and Methods for Simulation-Based Traffic Prediction2010In: TRB 89th Annual Meeting Compendium of Papers,, 2010Conference paper (Refereed)
  • 8.
    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.
    Andreasson, Ingmar
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics.
    Hybrid Mesoscopic-Microscopic Traffic Simulation2005In: Transportation Research Record, ISSN 0361-1981, E-ISSN 2169-4052, Vol. 1934, p. 218-225Article in journal (Refereed)
    Abstract [en]

    Traffic simulation is an important tool for modeling the operations of dynamic traffic systems. Although microscopic simulation models provide a detailed representation of the traffic process, macroscopic and mesoscopic models capture the traffic dynamics of large networks in less detail but without the problems of application and calibration of microscopic models. This paper presents a hybrid mesoscopic-microscopic model that applies microscopic simulation to areas of specific interest while simulating a large surrounding network in less detail with a mesoscopic model. The requirements that are important for a hybrid model to be consistent across the models at different levels of detail are identified. These requirements vary from the network and route choice consistency to the consistency of the traffic dynamics at the boundaries of the microscopic and mesoscopic submodels. An integration framework that satisfies these requirements is proposed. A prototype hybrid model is used to demonstrate the application of the integration framework and the solution of the various integration issues. The hybrid model integrates MlTSIMLab, a microscopic traffic simulation model, and Mezzo, a newly developed mesoscopic model. The hybrid model is applied in two case studies. The results are promising and support both the proposed architecture and the importance of integrating microscopic and mesoscopic models.

  • 9.
    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.

  • 10.
    Burghout, Wilco
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Rigole, Pierre Jean
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Andreasson, Ingmar
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Impacts of Shared Autonomous Taxis in a Metropolitan Area2015In: Proceedings of the 94th annual meeting of the Transportation Research Board, Washington DC, 2015Conference paper (Refereed)
    Abstract [en]

    The purpose of this paper is to provide an analysis of potential benefits of a fleet of shared autonomous taxis “aTaxis”, in this paper referred to as Shared Autonomous Vehicles  (SAV)) when replacing private car commuter trips in a metropolitan area. We develop a framework for dynamic allocation of SAVs to passenger trips, empty-vehicle routing and multi-criteria evaluation with regard to passenger waiting time, trip times and fleet size. Using a dynamic representation of current private vehicle demand for the Stockholm metropolitan area and a detailed network representation, different scenarios (varying levels of accepted passenger waiting time at origin and accepted % increase in travel time) are compared with respect to passenger travel time, number of vehicles needed and vehicle mileage. The results indicate that an SAV-based personal transport system has the potential to provide an on-demand door-to-door transport with a high level of service, using 5 % of today's private cars and parking places. In order to provide an environmental benefit and to reduce total mileage, an SAV-based personal transport system requires users to accept ride-sharing, allowing a maximum 30% increase of their travel time (13% on average) and a start time window of 10 minutes.

  • 11.
    Cats, Oded
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Larijani, Anahid Nabavi
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Ólafsdóttir, Ásdís
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Burghout, Wilco
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Andréasson, Ingmar J.
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Koutsopoulos, Harilaos N.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Bus-Holding Control Strategies Simulation-Based Evaluation and Guidelines for Implementation2012In: Transportation Research Record, ISSN 0361-1981, E-ISSN 2169-4052, no 2274, p. 100-108Article in journal (Refereed)
    Abstract [en]

    Transit operations involve several inherent sources of uncertainty, including dispatch time from the origin terminal, travel time between stops, and dwell time at stops. Bus-holding control strategies are a prominent method applied by transit operators to improve transit performance and level of service. The common practice is to regulate departures from a limited number of stops by holding buses until their scheduled departure time. An analysis of the performance of a high-frequency bus line in Stockholm, Sweden, based on automatic vehicle location data showed that this control strategy was not effective in improving service regularity along the line. The analysis also indicated that drivers adjusted their speed according to performance objectives. Implications of a control strategy that regulates departures from all stops on the basis of the headways of the preceding bus and the following bus were evaluated with Bus Mezzo, a transit operations simulation model. The results suggest that this strategy can improve service performance considerably from both passengers' and operator's perspectives. In addition, the strategy implies cooperative operations, as the decisions of each driver are interdependent with other drivers' decisions, and mutual corrections can be made. Difficulties in realizing the benefits of the proposed strategy in practice, such as dispatching from the origin terminal, driver scheduling, and compliance, are discussed. The implications of several practical considerations are assessed by conducting a sensitivity analysis as part of the preparations for a field experiment designed to test the proposed control strategy.

  • 12. Gunay, B.
    et al.
    Akgol, K.
    Andreasson, Ingmar
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Terzi, S.
    Estimation of modal shift potential for a new form of dial-a-ride service2016In: Journal of Public Transportation, ISSN 1077-291X, Vol. 19, no 2, p. 75-88Article in journal (Refereed)
    Abstract [en]

    The concept of a dynamic and flexible Intelligent Subscription Bus Service (I-Service) was developed, and two integrated questionnaires were conducted among the commuters of a large university campus. To determine travel times to the campus by I-Service, a digital urban road network map with travel time databases was produced, and software was developed to calculate optimum routes using these databases. Travel times for each participant were determined by the shortest travel time principle. The proposed hypothetical service was introduced to participants, and anticipated advantages for each participant were reported back to them by means of a second questionnaire to determine if they would prefer using I-Service. As a result, a 49% modal shift potential from all other modes in general and a 52% modal shift potential from private car to I-Service were found.

  • 13. Jie, L.
    et al.
    Sen, C. Y.
    Hao, L.
    Andreasson, Ingmar
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Van Zuylen, H. J.
    Optimizing the fleet size of a personal rapid transit system: A case study in port of Rotterdam2010In: 2010 13th International IEEE Conference on Intelligent Transportation Systems (ITSC), IEEE , 2010, p. 301-305Conference paper (Refereed)
    Abstract [en]

    Cost issues have been an important concern in the development of Personal Rapid Transit (PRT) since the concept was developed several decades ago. The lightweight, computer-guided electric vehicles operating the PRT system are generally a major part of the capital cost of the system, especially in larger network with high demand. A sufficient number of empty vehicles are needed to be moved to the stations where passengers are waiting or demand is expected. Generally a larger fleet size leads to a reduction in waiting time of passengers and thus a higher level of service given a specific demand, but an increased investment cost including capital cost per vehicle and additional operation and maintenance. So it requires a compromise between user cost (in terms of passenger waiting times) and operator cost (in terms of fleet sizedependent capital cost and operating/maintenance costs). There should be an optimal fleet size so that the sum of these two costs can be minimized while an expected level of service is achieved. This paper presents first the way to obtain the PRT demand, and then a prescription to determine the optimal fleet size using a cost-effectiveness analysis with traffic simulation. This prescription identifies the set of activities that are necessary to perform the optimization task. Each activity is regarded as a component in our general framework and this framework is illustrated by a case study in the Waal/ Eemshaven harbor area in the Port of Rotterdam, The Netherlands.

  • 14.
    Ma, Xiaoliang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Andreasson, Ingmar
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Behavior measurement, analysis and regime classification in car following2007In: IEEE transactions on intelligent transportation systems (Print), ISSN 1524-9050, E-ISSN 1558-0016, Vol. 8, no 1, p. 144-156Article in journal (Refereed)
    Abstract [en]

    This paper first reports a data acquisition method that the authors used in a project on modeling driver behavior for microscopic traffic simulations. An advanced instrumented vehicle was employed to collect driver-behavior data, mainly car-following and lane-changing patterns, on Swedish roads. To eliminate the measurement noise in acquired car-following patterns, the Kalman smoothing algorithm was applied to the state-space model of the physical states (acceleration, speed, and position) of both instrumented and tracked vehicles. The denoised driving patterns were used in the analysis of driver properties in the car-following stage. For further modeling of car-following behavior, we developed and implemented a consolidated fuzzy clustering algorithm to classify different car-following regimes from the preprocessed data. The algorithm considers time continuity of collected driver-behavior patterns and can be more reliably applied in the classification of continuous car-following regimes when the classical fuzzy C-means algorithm gives unclear results.

  • 15.
    Ma, Xiaoliang
    et al.
    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 Traffic Research, CTR.
    Andreasson, Ingmar
    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 Traffic Research, CTR.
    Driver reaction delay estimation from real data and its application in GM-type model evaluation2006Conference paper (Refereed)
  • 16.
    Ma, Xiaoliang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301). KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Andreasson, Ingmar
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301). KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Dynamic car following data collection and noise cancellation based on the Kalman smoothing2005In: 2005 IEEE International Conference on Vehicular Electronics and Safety Proceedings, 2005, p. 35-41Conference paper (Refereed)
    Abstract [en]

    This paper will introduce a data collection method that we used in a project on modeling driver behavior in microscopic traffic simulation. A modern instrumented vehicle was employed to study a crucial element of driver behavior, that of car following, on Swedish roads. The collected car following data shows noisy patterns. To eliminate the measurement noise, Kalman smoothing algorithm is applied to the state-space formulation of the physical states (acceleration, speed and position) of tracked vehicles. The smoothed data shows clear car following patterns and has been further applied in our car following model calibration and validation study.

  • 17.
    Ma, Xiaoliang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301). KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Andreasson, Ingmar
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301). KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Estimation of driver reaction time from car-following data - Application in evaluation of general motor-type model2006In: Traffic Flow Theory 2006, 2006, no 1965, p. 130-141Conference paper (Refereed)
    Abstract [en]

    Driver behavior plays an important role in modeling vehicle dynamics in a traffic simulation environment. To study one element of general driver behavior, that of car following, an advanced-instrumented vehicle has been applied in dynamic data collection in real-traffic flow on Swedish roads. This paper briefly introduces the car-following data collection and smoothing methods. Moreover, spectrum analysis methods based on Fourier analysis of car-following data are introduced to estimate driver reaction times, a crucial parameter of driver behavior. A generalized general motor-type model was calibrated, an extension of the classic nonlinear general motor model, in a stable following regime based on estimated driver reaction times. The calibrated model was then evaluated by closed-loop simulations.

  • 18.
    Ma, Xiaoliang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Andreasson, Ingmar
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Predicting the effect of various ISA penetration grades on pedestrian safety by simulation2005In: Accident Analysis and Prevention, ISSN 0001-4575, E-ISSN 1879-2057, Vol. 37, no 6, p. 1162-1169Article in journal (Refereed)
    Abstract [en]

    Intelligent speed adaption (ISA) is one type of vehicle-based intelligent transportation systems (ITS), which warns and regulates driving speed according to the speed limits of the roads. Early field studies showed that ISA could reduce general mean speed levels and their variances in different road environments. This paper studies the effects of various ISA penetration grades on pedestrian safety in a single lane road. A microscopic traffic simulation tool, TPMA, was further developed and used to implement different ISA penetration grades. Momentary spot speed and traffic flow data are first logged in the traffic simulation for later prediction of pedestrian safety. Then a hypothetical vehicle-pedestrian collision model is extended from early researches in order to estimate two safety indicators: probability of collision, and risk of death. Finally, Monte Carlo method is applied iteratively to compute those safety indices. The computational result shows that raising ISA penetration in traffic flow will reduce both the probability of mid-block collision between vehicle and pedestrian and the risk of death in the collision accidents. Furthermore, the decrease of the risk of death will be more prominent than that of the collision probability according to this method.

  • 19.
    Ma, Xiaoliang
    et al.
    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 Traffic Research, CTR.
    Andreasson, Ingmar
    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 Traffic Research, CTR.
    Statistical analysis of driver behavioral data in different regimes of the car-following stage2007In: TRB 86th Annual Meeting Compendium of Papers CD-ROM, 2007Conference paper (Refereed)
  • 20.
    Ma, Xiaoliang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Andreasson, Ingmar
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Statistical analysis of driver behavioral data in different regimes of the car-following stage2007In: Transportation Research Record, ISSN 0361-1981, E-ISSN 2169-4052, no 2018, p. 87-96Article in journal (Refereed)
    Abstract [en]

    An instrumented vehicle has been used to study car-following behavior on Swedish motorways. In this study, the previous data collection and pre-processing work were briefly reviewed. To understand the driving behavior in the car-following stage more clearly, the collected time series were classified into a number of regimes using unsupervised fuzzy clustering methods. Then, the statistical relations between the driver acceleration response and the perceptual variables in each regime were analyzed using correlation and regression methods. It was found that regime classification helps discern the behavioral variance between those regime clusters. According to the data analysis, some of the car-following regimes, for example, opening and braking, can be described adequately in the statistical sense by a linear regression model (Helly's model). Therefore, a multiple regime car-following model with simple model forms, for example, linear models, has the potential to robustly represent the general car-following behavior in most regimes.

  • 21.
    Ma, Xiaoliang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Andréasson, Ingmar
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Driver reaction delay estimation from real data and its application in GM-type model evaluation2006In: Transportation Research Record, ISSN 0361-1981, E-ISSN 2169-4052, no 1965, p. 130-141Article in journal (Refereed)
    Abstract [en]

    Driver behavior plays an important role in modeling vehicle dynamics in a traffic simulation environment. To study one element of the general driver behavior, that of car following, an advanced instrumented vehicle has been applied in dynamic data collection in real traffic flow on Swedishroads. This paper briefly introduces our car following data collection and smoothing methods. Moreover, we introduce spectrum analysis methods based on Fourier analysis of car following data to estimate driver reaction times, a crucial parameter of driver behavior. As an example, we calibrate a generalized GM-type model, an extension of the classical nonlinear GM model, in stable following regime based on the estimated driver reaction times. The calibrated model is then evaluated by closed-loop simulations.

  • 22.
    Ma, Xiaoliang
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics.
    Burghout, Wilco
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics.
    Andreasson, Ingmar
    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.
    Evaluation of Real-Time Travel Time Estimation Methods and Disruption Warning Using Noisy Automatic Vehicle Identification Measurements2009In: Transportation Research Board Annual Meeting 2009 Paper: Transportation Research Board 88th Annual Meeting, Washington D.C., Jan. 2009, 2009Conference paper (Refereed)
    Abstract [en]

    To support the implementation of a real-time traffic information system in Stockholm using automatic vehicle identification (AVI) data, a travel time analysis platform has been developed. The platform is composed of a client-side travel time data analysis program and a database server where historical travel time data are stored. In the study, several existing freeway travel time estimation algorithms and their modifications were implemented in the travel time analysis program, and evaluated using four months data collected on urban streets and arterials in and near the city of Stockholm. The advantages and disadvantages of those algorithms are analyzed using the highly noisy travel time measurements. The results show that with modifications in the parameter settings and the algorithms themselves, the methods are capable of estimating the travel times from the noise-corrupted urban data. In addition to the travel time estimation, the paper presents a simple data disruption recognition approach on the way toward a more comprehensive disruption and incident warning system.

  • 23.
    Ma, Xiaoliang
    et al.
    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 Traffic Research, CTR.
    Huang, Zhen
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Zaman, Abdul
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Andreasson, Ingmar
    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 Traffic Research, CTR.
    A Prototype Distributed Simulation Platform for Online Traffic Emission Predictions2009In: proceeding and CD of the 10th International Conference in Computers on Urban Planning and Urban Managements, 2009Conference paper (Refereed)
  • 24.
    Ma, Xiaoliang
    et al.
    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 Traffic Research, CTR.
    Lei, Wei
    Andreasson, Ingmar
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.
    Chen, Hui
    An Evaluation of Microscopic Emission Models for Traffic Pollution Simulation Using On-board Measurement2012In: Environmental Modelling and Assessment, ISSN 1420-2026, E-ISSN 1573-2967, Vol. 17, no 4, p. 375-387Article in journal (Refereed)
    Abstract [en]

    As a result of the continuously increasing numbers of motor vehicles in metropolitan areas worldwide, road traffic emission levels have been recognized as a challenge during the planning and management of transportation. Experiments were conducted to collect on-road emission data using portable emission measurement systems in two Chinese cities in order to estimate real traffic emissions and energy consumption levels and to build computational models for operational transport environment projects. In total, dynamic pollutant emissions and fuel consumption levels from dozens of light duty vehicles, primarily from four different vehicle classes, were measured at a second-by-second level. Using the collected data, several microscopic emission models including CMEM, VT-Micro, EMIT, and POLY were evaluated and compared through calibration and validation procedures. Non-linear optimization methods are applied for the calibration of the CMEM and EMIT models. Numerical results show that the models can realize performance levels close to the CMEM model in most cases. The VT-Micro model shows advantages in its unanimous performance and ability to describe low emission profiles while the EMIT model has a clear physics basis and a simple model structure. Both of them can be applied when extensive emission computation is required in estimating environmental impacts resulting from dynamic road traffic.

1 - 24 of 24
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf