Presentation on theme: "NEXTA: Network EXplorer for Traffic Analysis"— Presentation transcript:
1Step-by-Step Tutorial NEXTA: Simulation Data Visualizer for Open-Source DTALite Engine NEXTA: Network EXplorer for Traffic AnalysisThis tutorial is prepared byDr. Xuesong Zhou and Mingxin Li at Univ. of Utah
2Major Components of Software Package DTALite: Open-source Assignment/Simulation EngineDTALite is a fast open-source dynamic traffic assignment engine, which aims to assist transportation planners to effectively utilize advanced dynamic traffic analysis tools with limited hardware and time resources. It uses a computationally simple but theoretically rigorous traffic queuing model in its lightweight mesoscopic simulation engine.DTALite is distributed as open-source software using the GNU General Public License (GPL). Its source code is available atNEXTA: GUI for Visualization and Data PreparationNEXTA (Network EXplorer for Traffic Analysis) is a graphical user interface to facilitate preparation, post-processing and analysis of simulation-based dynamic traffic assignment datasets. NEXTA is extended from DYNASMART-P Graphical Input Editor (DSPEd) 1.0, which was initially developed by ITT Industries, Inc. for the Federal Highway Administration (FHWA) in Dr. Xuesong Zhou has been maintaining and enhancing its capabilities since then. NEXTA is distributed as Freeware, and it is now also used as the visualization program for TRANSIMS, an open-source software package for transportation analysis and simulation.
3Sample Data Set: Portland Network and Demand Data # of Zones = 2,013# of Nodes = 10,094# of Links = 25,804# of Vehicles = 1.1M for 4 hoursComputer Settings:Intel Core 2 Duo CPU(2 processors)2.26 GHz4 GB of RAMTotal computation time for 10 iterations: 4 hoursComputation time per iteration: 24 min
8Tutorial Outline Software installation Exercise 1: View simulation resultsExercise 2: Running traffic simulation and understand output filesExercise 3: Prepare input data from Excel spreadsheet
9Install NEXTA for DTALite (1) Step 1: Install NEXTA“C:\Program Files\NEXTA_for_DTALite”Step 2: Install Visual C redistribution packageGo to folderC:\Program Files\NEXTA_for_DTALite \VisualC++_RedistributionPackageand click on “vcredist_x86.exe” to install.Step 3: Install “Data Access Object” redistribution packageGo to C:\Program Files\ NEXTA_for_DTALite\VisualC++_RedistributionPackage\DISK1, click on “Setup.exe” to install.
10Install NEXTA for DTALite (2) Remarks:You need an Administrator account to install the NEXTA package.Please save your DTALite data set to a “writable” folder (e.g. C:\DTALite\DataSets\”. Folder “Program Files” could be set to “read-only” by your Windows operating systems.Please visitfor the latest NEXTA for DTALite software release and additional data set.4) The release data of your current NEXTA package can be found at menu -> Help -> About.
11Details at Installation Folder Dynamic Traffic Assignment EngineDatasetsGraphical User Interface
12Hardware and Software Requirements Hardware recommendationsMinimum memory of 512 MB.Recommended options for large-scale network: 4GB of RAMRemarks: An insufficient amount of RAM can cause your computer to continually read data from disk instead of physical memory, please ensure there is sufficient memory for very large networks.Operating system requirementsWindows 2000Windows XPWindows Vista (32 bit/64 bit)Windows 7
13Exercise 1: Visualization What we will learn:Step 1: Import Data from Excel SpreadsheetStep 13: Multi-link ComparisonStep 2: Save a projectStep 14: Network-level MOEStep 3: Run Traffic Simulation/AssignmentStep 15: Vehicle-path AnalysisStep 4: Resize the NetworkStep 16: Find Paths in NEXTAStep 5: Double-Click a Link to Show Link PropertyStep 17: View Summary.logStep 19: Change Link CapacityStep 6: Display Capacity and Demand AttributesStep 20: Save the changesStep 21: Re-run SimulationStep 7: Select Display Mode to View Simulation Results (Density, Speed, Queue and Volume)Step 22: Save to Another FolderStep 23: Re-load previous datasetStep 24: Compare Capacity Change VisuallyStep 8: Select Vehicle Display ModeStep 25: Compare Network MOEsStep 9: Show Simulation Results at a Given Time PeriodStep 26: Run Simulation: Check Network-level MOEStep 10: Play AnimationStep 27: Check Link-level MOEStep 11: Double-Click a Link to Show MOE ProfileStep 28: Locate Other MOE filesStep 29: Read On-line DocumentStep 12: Configure MOE Display Dialog
14Step 1: Import Data from Excel Spreadsheet Filename: SampleNetwork.xlsDataset folder: C:\Program Files\NEXTA_for_DTALite\DataSetsThe data structure of the spreadsheet will be explained in Exercise 3.
15Step 2: Save a projectSuggested folderC:\DTALite\DataSets\Sample2
43Advanced Topic 1:Scenario ConfigurationLocate major output files
44Step 1: Configuring DTASettings.ini Global multiplication factor will multiply each OD pair by that factor.
45Running Simulation: Illustration of Demand Loading/Simulation Horizon, Departure Time Interval
46Step 2: View AssignmentMOE.csv IterationTime stamp in minuteCumulative in-flow countCumulative out-flow countNumber of vehicles in the networkFlow in a minuteAverage trip-time in minuteThe simulation results can be divided into three types: the individual link performance, vehicle trajectory and network performance.
47Step 3: LinkMOE.csv Iteration From-node ID To-node ID Timestamp in minuteTravel time in minuteDelay in minuteLink volume in vehicleLink volume in vehicle/hour/lane (vehphpl)Density in vehicle/mile/laneSpeed in mphExit queue lengthCumulative arrival countCumulative departure count
48Step 4: Vehicle.csv Iteration Occupancy Vehicle ID Information type Origin zone IDValue of timeDestination zone IDMinimum path costDeparture timeDistance in mileArrival timeNumber of nodesComplete flagNode idTrip timeNode arrival timeVehicle type