AIRE Analysis of Instantaneous Road Emissions -...

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AIRE

Analysis of Instantaneous Road Emissions

User Guidance

June 2011 Transport Scotland

Transport Scotland AIRE User Guidance


Contents

1 Introduction .............................................................................................................................. 1

1.1 Background .............................................................................................................................. 1

1.2 Use of AIRE ............................................................................................................................. 1

1.3 AIRE & Microsimulation Models............................................................................................... 2

1.4 Further Information................................................................................................................... 2

1.5 Support..................................................................................................................................... 2

1.6 Acknowledgements .................................................................................................................. 3

2 Environmental Assessment...................................................................................................... 4

2.1 Introduction .............................................................................................................................. 4

2.2 Air Quality................................................................................................................................. 4

2.3 Further Information................................................................................................................... 4

3 Application of AIRE .................................................................................................................. 5

3.1 Overview .................................................................................................................................. 5

3.2 Define the Modelled Year......................................................................................................... 5

3.3 Specify the Model Folder ......................................................................................................... 6

3.4 Project Settings ........................................................................................................................ 7

3.5 Specifying Outputs ................................................................................................................... 8

3.6 Running the Processor............................................................................................................. 9

3.7 Project Configuration.............................................................................................................. 10

3.8 Menu Bar................................................................................................................................ 11

3.9 Processor Input and Output Files .......................................................................................... 12

3.10 Running in Batch Mode.......................................................................................................... 14

APPENDIX A: Input and Output File Formats ............................................................................................ 16


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1 INTRODUCTION

1.1 Background

1.1.1 AIRE (Analysis of Instantaneous Road Emissions) is an ancillary software program specifically designed to process the outputs from traffic microsimulation models and calculate vehicle emissions. AIRE incorporates over 3,000 Instantaneous Emissions Modelling (IEM) tables which are used to estimate tailpipe emissions from individual simulated road vehicles. The IEM tables were derived from PHEM (Passenger car and Heavy Duty Emissions Model), which was developed by the Technical University of Graz. PHEM is a vehicle dynamics model with engine maps, enabling emissions to be output for various engine speeds and engine loads.

1.1.2 AIRE can be used to process the detailed, vehicle by vehicle outputs produced by microsimulation models and provides significantly more disaggregate and detailed emissions estimates compared with traditional, average speed-based methods.

1.1.3 AIRE produces estimates of the oxides of nitrogen, particulate matter and total carbon that result from the combustion of fuel throughout each simulated vehicle’s journey. The estimates are produced on a simulated time step by time step basis, so the detail and quality of the resulting output emissions estimates are directly related to the adopted simulation’s fidelity and robustness.

1.1.4 AIRE uses outputs from a microsimulation model. Unlike conventional deterministic or equilibrium models, the outputs from a microsimulation model do not converge to a single solution, but vary each time the model is run (depending on the random number seed used in each run). It is important that provision is made for the degree of uncertainty in the microsimulation models through undertaking a number of model runs for each scenario. Sufficient runs should be undertaken to ensure stability and robustness of the model outputs, although the actual number of runs required will be dependent on the specific analysis being undertaken, time/budget implications and any other constraints of the modelling exercise to be undertaken.

1.1.5 The estimates produced by AIRE are for tailpipe emissions and do not include the impact of dispersion within the atmosphere, ambient factors, such as weather and temperature, or the local built environment.

1.2 Use of AIRE

1.2.1 AIRE has been developed by SIAS Limited (SIAS) in collaboration with the Transport Research Laboratory (TRL). Transport Scotland will maintain AIRE in the future as its vehicle emissions analysis program for use with microsimulation models. The software development was undertaken by SIAS with the calculated outputs from the program independently verified by TRL. Following this verification, further testing was undertaken making use of modelled and observed vehicle trace data. Emissions estimates from AIRE were also independently compared against those obtained by traditional, average speed-based methods using real project examples.

1.2.2 Users outside Scotland should check with the appropriate overseeing organisation to ensure that it is appropriate and acceptable to use AIRE.


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1.3 AIRE & Microsimulation Models

1.3.1 Although AIRE has been specifically designed such that it can be used directly with outputs from S-Paramics, it can be used with other microsimulation traffic models, provided the outputs from the models are in the correct format for input to AIRE.

1.3.2 The combination of microsimulation traffic modelling and AIRE provides a robust emissions modelling tool in that various aspects of traffic operation can be captured in greater detail and with potentially greater accuracy than traditional average speed-based methods of estimating emissions. This includes:

Information on a much wider range of engines conforming to EU emission standards,

Factors for a wide range of heavy vehicles (HGVs, buses, coaches, etc.),

Disaggregation of the information by vehicle load and gradient, enabling overall engine load effects on emissions outputs to be reflected,

A high level of flexibility in coding and modelling the operating characteristics of different vehicle types (e.g. light, medium and heavy vehicles, public service and slow moving vehicles),

Accurate representation of the variation in traffic flows using time-based profiles of travel demand by vehicle type and origin/destination (e.g. different traffic flow profiles can be used for different movements and/or directions),

Detailed modelling of individual vehicles and the interaction between for example cars and slower moving vehicles at junctions, in platoons, and during overtaking manoeuvres (e.g. more robust outputs for environmental assessment including the representation of variation in acceleration and speed within each individual trip, identification of downstream impacts and benefits etc.),

1.4 Further Information

1.4.1 Appendix A provides a definition of the file formats required as input to AIRE and for the resulting output files. Example input and output files are also included with the AIRE installation.

1.4.2 Further background documentation relating to environmental assessment can be found in the Design Manual for Roads and Bridges (DMRB) Volume 11, the DfT’s Transport Analysis Guidance (TAG) and the Scottish Transport Appraisal Guidance (STAG).

1.5 Support

1.5.1 AIRE is supported by SIAS. If users require any assistance or further information regarding AIRE, please email [email protected].


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1.6 Acknowledgements

1.6.1 SIAS wishes to acknowledge the work of Dr Ian S McCrae whose expertise contributed over many years to the advancement of research in this field. The assistance of the Technical University of Graz in allowing access to the IEM data from PHEM and Glasgow City Council’s cooperation in granting permission to use its microsimulation model in the project is also greatly appreciated


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2 ENVIRONMENTAL ASSESSMENT

2.1 Introduction

2.1.1 The environmental assessment of transport schemes and policies is an essential element of the overall appraisal process. Environmental assessment itself covers a wide range of differing issues including noise & vibration, air quality, ecology, cultural heritage, landscape and drainage amongst others.

2.1.2 AIRE can be used in support of analysis undertaken to examine air quality impacts.

2.2 Air Quality

2.2.1 Assessing the air quality impacts of transport schemes and policies has traditionally been undertaken using aggregate traffic assignment models which provide outputs relating to average vehicle speeds on individual links and/or for entire journeys. Relatively simple relationships between average speed and fuel consumption for a given vehicle type can then be used to estimate the amount of fuel consumed and consequently the vehicle emissions. While simple to apply and a quick and effective means of producing an estimate, these methods may not adequately reflect:

Variations in individual vehicle speeds on links or along entire journeys

Impacts of speed and acceleration in stop-start conditions

The effect of gradients

The detail of the vehicle fleet and operating characteristics (i.e. engine type/size, fuel type, vehicle loadings, etc.)

2.2.2 These limitations are recognised in the published guidance and DMRB Volume 11, Section 3, Part 1, HA207/07 Annex E specifically states:

It may be necessary to use an ‘instantaneous’ emission model, in which emissions are related to vehicle operation.

2.2.3 The guidance goes on to mention PHEM and the need to use microsimulation in such cases. AIRE is a means of providing an automated capability to calculate the vehicle emissions for situations where a more detailed assessment is required and a microsimulation model is available. This detailed information can then be used to support the air quality impact assessment.

2.3 Further Information

2.3.1 The DMRB Volume 11 provides detailed guidance on environmental assessment. The specific detailed guidance relating to air quality is outlined in DMRB Volume 11, Section 3, Part 1, HA207/07. The DfT’s Transport Analysis Guidance website (http://www.dft.gov.uk/webtag) is another useful source of information with Units 3.3.3 to 3.3.5 being particularly relevant to emissions modelling and assessment. STAG Section 4.2 also provides information on environmental assessment in a Scottish context.


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3 APPLICATION OF AIRE

3.1 Overview

3.1.1 As outlined in Section 1, AIRE can be used with any traffic microsimulation model, provided that the outputs from the model are in the correct input format for AIRE.

3.1.2 The layout of AIRE enables the user to easily specify the data inputs and settings required to calculate the vehicle emissions for a given model. The basic steps involved are:

Specify the modelled year

Locate the required model folder in the directory structure

Specify the model outputs to be processed by AIRE

Modify the vehicle fleet distribution, if required

Specify sub-sets of links for analysis, if required

Specify the required outputs from AIRE

Note: The options specified at this stage can be saved to a project which can be re-used or amended at any time.

3.1.3 Once the relevant inputs and settings are specified the processing can be started and the progress monitored from the same input screen.

3.2 Define the Modelled Year

3.2.1 The input tab, as shown in Figure 3.1, allows the user to specify the year for which the microsimulation model has been run. This will ensure that the appropriate vehicle fleet distribution is selected and used in the calculations. Default fleet distribution values for each year from 1996 to 2025 have been incorporated in AIRE based on information from the National Atmospheric Emissions Inventory (Ref. http://www.naei.org.uk/other/uk_fleet_composition_projections_v2.xls). This includes values for the split by fuel type, vehicle load, vehicle/engine size & location and by EU emission standard.

Figure 3.1 : AIRE Input Tab


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3.3 Specify the Model Folder

3.3.1 By selecting the “…” button at the right end of the Folder dialog the Browse For Folder dialog will be displayed. This dialog is shown in Figure 3.2.

Figure 3.2 : Browse For Folder Dialog

3.3.2 The user should navigate to the directory containing the model for which the emissions calculations are to be undertaken. The program will automatically look in the \Log sub-directory for any folders containing output statistics from individual model runs, which should be in named run-001, run-002…run-nnn (where nnn is any number up to 999). If the appropriate files are detected the input tab will be displayed as shown in Figure 3.3.


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Figure 3.3 : Input Tab With Model Folder Specified

3.3.3 Once the input model has been specified and the appropriate files detected, the user can create a project by using File>>Save or Save As and specifying the appropriate location and filename. The default project location suggested by the program will be in the model directory for the currently loaded model and the project is saved as a file with a .epp extension. The project can then be amended, saved, reloaded, etc. without the need for the user to re-specify all of the required inputs and outputs each time.

Note: The model folder must contain a text file named nodes (with no file extension) and a sub-directory called Log which must contain further sub-directories named run-001 to run-nnn. representing each of the individual runs for which the emissions calculations are required. If any of these files/folders are not detected a warning will be issued and the selected model folder will not be accepted as input to AIRE.

3.4 Project Settings

3.4.1 There are various settings that the user can adjust prior to running the processor and calculating the emissions. Each of these settings will have an effect on the resulting emissions output calculations and it is important for the user to ensure that the appropriate settings are applied each time the processor is run. The options are:

Select model runs… This enables the individual model runs, undertaken with different random seed values, to be selected as appropriate. The output emissions calculations will be produced for each run individually and the user may combine/average the subsequent outputs as appropriate.

Modify fleet distribution… The default fleet distribution (Ref. Section 3.2) can be modified with this option. Clicking this button opens the spreadsheet containing the fleet distribution in MS Excel, from where any modifications to the default fleet distribution settings can be saved as appropriate. For the modified fleet distribution to take effect in AIRE a new .xml file must be created using the spreadsheet, which must then be linked to the project via the Project Configuration… option


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Select links for summary… Clicking this button opens a new dialog in which a full list of all network links will be displayed. The user then has the option to include or exclude specific links from the list of those that will be reported if the Link summaries output option is chosen. The selected link settings can be saved for the current project

Note: To make use of the Select links for summary… option, a text file called links (with no file extension) must be located in the model directory specifying the links in the model network. Each line of this file should contain the details of a single link using the syntax link Anode Bnode.

3.4.2 Once the relevant processing settings have been specified it is recommended that the current project is saved prior to running the processor.

3.5 Specifying Outputs

3.5.1 The user should use the check boxes to select which of the outputs are required from AIRE. The processor cannot be run unless the check box for least one output option is selected. For all output types the processor writes additional data in the relevant output files showing the calculated amounts of oxides of nitrogen, particulate matter and total carbon in each case. All estimates are produced in milligrams.

3.5.2 There are four different output options available to the user, namely:

OD and path trips The total quantity of emissions calculated for each vehicle assigned using demand matrices or fixed path demands, aggregated for the entire trip

PT trips The total quantity of emissions calculated for each Public Transport vehicle assigned using fixed route & timetable information, aggregated for the entire trip

Time step data The quantity of emissions calculated for each vehicle (whether assigned using demand matrices, fixed path demands or fixed route & timetable information) at each simulated time step

Link summaries The quantity of emissions calculated for each link by vehicle type (whether assigned using demand matrices, fixed path demands or fixed route & timetable information) and fuel type, aggregated along the entire link

Note: Link summaries output will contain information only for the list of Included links specified via the Select links for summary… option. Users should take care to ensure that all links for which this information is required are included in the list prior to running AIRE.


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3.6 Running the Processor

3.6.1 Once the relevant inputs are correctly specified the processor can be run to undertake the emissions calculations by clicking on the start button which is outlined in red in Figure 3.4.

Figure 3.4 : Emissions Processor Start Button

3.6.2 The current progress of the processing will automatically be displayed, showing the number of files and model runs that have been processed. Further details of the processing can be obtained by clicking on the Details button, as shown in Figure 3.5.


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Figure 3.5 : Further Details of Processing

3.6.3 The user can view details of the outputs, or any errors that occur as the processor runs, on the respective tabs. An option exists to expand the level of detail provided by clicking on the Verbose output check box. The user should note that this will slow down the speed of the processor and may result in significant disk space usage. The details can also be saved to a file by clicking on the Save output check box and specifying the filename and location before running the processor.

3.7 Project Configuration

3.7.1 A list of advanced settings can be accessed by clicking on the Project Configuration… button at the bottom left of the main dialog. The default advanced settings for an installation to a local C:\ drive are shown in Figure 3.6.


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Figure 3.6 : Project Configuration Dialog

3.7.2 The default settings can be overridden by selecting any of the check boxes in the Default column to remove the tick. This will enable the relevant filenames, folder settings and file thresholds to be edited accordingly. The default settings can be restored at any time by clicking on the Defaults button.

Note: It is recommended that the default settings are used where possible to limit the scope for error. Where non-default data file and folder settings are used it is the user’s responsibility to ensure that these are correctly specified and that the processor produces outputs consistent with the specified changes to the default settings.

3.8 Menu Bar

3.8.1 There are various options to choose in the menu bar along the top of the main dialog and these are described as follows.

File Menu

3.8.2 The options available under the File menu are:

New : Starts a new project.

Open : Opens an existing project.

Save : Saves the current specified settings to an existing project.

Save As : Saves the current specified settings to a new project file specified by the user.

Exit : Closes the program. The Exit button on the main dialog can also be used for this purpose. The user is prompted to save any changes before exiting.


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Processor Menu

3.8.3 The options available under the Processor menu are:

Run : Becomes available only if the appropriate settings and inputs are specified and will run the processor.

Stop : Becomes available only if the processor is currently running and will stop the processor.

Project Configuration… : Accesses the advanced settings for the project.

Clear output : Clears any information on the Output tab accessed via the Details button.

Clear errors : Clears any information on the Errors tab accessed via the Details button.

Help Menu

3.8.4 The options available under the Help menu are:

User Guide : Opens a copy of this user guidance document.

Command Line Options : This provides guidance on the options and syntax available when running the processor via a command line rather than via the graphical user interface (GUI).

About : Provides basic information about the installed version of the processor. This can also be accessed via the About button on the main screen.

3.9 Processor Input and Output Files

3.9.1 The various input and output files relevant to the processor are summarised in this section. It is recommended that this section is read in conjunction with the demonstration model provided with the AIRE installation. The default installation location for this model is %UserProfile%\My Documents\AIRE\Demo Model.

3.9.2 In all cases the basic calculations are undertaken by AIRE on a simulated time step by time step basis using the carpositionsNNNNNN.csv (where NNNNNN is between 000001 and 999999) files in the directories containing the microsimulation model original output files (\Log\run-nnn). AIRE will aggregate the calculated emissions data depending on which output options were selected for the project.

OD and path trips

3.9.3 Details for each trip (excluding fixed route/timetabled public transport trips) are contained in the file called trips-ALL.csv which includes information such as vehicle type, origin zone, destination zone, travel time and travel distance. When this output option is selected a new file called trips-ALL-AIRE.csv will be created in the same directory as the original file. This is a copy of the original file, but updated to include information on the fuel type and vehicle characteristics assigned from the fleet distribution in AIRE and the calculated emissions aggregated for each trip.


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PT trips

3.9.4 Details for each fixed route/timetabled public transport (PT) trip are contained in the file called busdelay.csv, which includes information such as start time, travel time, travel distance and bus stop departure times. When this output option is selected a new file called busdelay-AIRE.csv will be created in the same directory as the original file. This is a copy of the original file but updated to include information on the fuel type and vehicle characteristics assigned from the fleet distribution in AIRE and the calculated emissions aggregated for each PT trip.

Time step data

3.9.5 The time step data is stored in files called carpositionsNNNNNN.csv and contains information for each simulated time step for each individual vehicle in the simulation. The stored information includes time step, link, unique tag number identifying each vehicle, speed, acceleration and gradient. The carpositionsNNNNNN.csv files contain this information for all simulated vehicles whether they are fixed route/timetabled PT trips or assigned either via trip matrices or fixed paths. There may be multiple carpositionsNNNNNN.csv file for each model run to keep individual file sizes manageable.

3.9.6 When this output option is selected each carpositionsNNNNNN.csv file will be updated to include the calculated emissions for each simulated time step. Due to the potential for significant disk space usage a separate copy of these files is not created and the original files are simply updated to include the relevant calculated emissions values.

3.9.7 The carpositionsNNNNNN.csv files can be reprocessed by AIRE even if they have previously been processed. In cases where these files have been processed more than once the data in the columns relating to the calculated emissions values will be marked with an asterisk (*).

Note: To save disk space the carpositionsNNNNNN.csv files may be limited to include only the information related to vehicles on selected links. Users should take note that if the carpositionsNNNNNN.csv files input to AIRE are limited in this way, the OD and path trips and PT trips outputs from AIRE will also be limited to include only the emissions estimates for the parts of each trip related to this subset of links. The default Failed record abort file threshold setting of 100 in the Project configuration… may also need to be increased to allow the processing to be completed where collection of car positions has been limited to a specific subset of links.

Link summaries

3.9.8 Selecting this option will result in an additional output file in the output (Log\run-nnn) directories called emissions_link_summary.csv. This presents the quantity of emissions calculated for each link disaggregated by vehicle type (whether assigned using demand matrices, fixed path demands or fixed route & timetable information) and by fuel type aggregated along the entire link.

3.9.9 An overview of the input and output file formats is provided in Appendix A while example files can be seen in the demonstration model provided with the AIRE installation.


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3.10 Running in Batch Mode

3.10.1 In addition to running interactively via the GUI, AIRE can also be run in batch mode using command line options. This provides great flexibility to the user meaning that AIRE can be setup to automatically run a number of repetitive actions and/or to run as part of a coordinated sequence (e.g. to run immediately upon completion of the required model runs).

3.10.2 The command line options available can be viewed by selecting Help>>Command Line Options from the menu bar. An overview of the command line options is provided in this section. In addition a sample batch script, AIRE Batch Processor Sample Script.bat is installed in the AIRE sub-folder of the user’s My Documents folder. The sample script runs the installed demo model project file.

3.10.3 There are two different executable files that can be run using batch mode:

AIREGUIProcessor.exe : GUI Processor: This runs the standard AIRE program with the graphical user interface

AIREBatchProcessor.exe : Batch Processor: This runs AIRE with no graphical user interface

3.10.4 For a standard installation, these executable files are stored in the C:\Program Files\AIRE\bin\ directory. Example syntax for running in batch mode is provided throughout this section.

"c:\Program Files\AIRE\bin\AIREBatchProcessor"

or

"c:\Program Files\AIRE\bin\AIREGUIProcessor"

Note: Inverted commas required where path includes spaces.

3.10.5 The processor also accepts various additional command line options. The options and example syntax are:

-project : Enables a .epp project file to be specified for use with the processor. Required for successful operation of the Batch Processor.

-project C:\models\data\Emissions_Model\aire-project.epp

-model : Optional, enables the model directory containing the outputs for processing to be specified. Supersedes any model directory specified in the .epp project.

-model C:\models\data\Emissions_Model


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-help : Optional, launches the Help>>Command Line Options dialog (or prints this as a message in the command window if used with AIREBatchProcessor.exe).

-help

-output : Optional and for use with Batch Processor only. Enables an output file to be specified to write command prompt messages to

-output C:\temp\output.txt

-run Optional and for use with GUI Processor only. Sets the processor running immediately on opening (the Batch Processor always starts running as soon as it has opened the project file).

-run

-save : Optional, overwrites the .epp project file after running

-save

3.10.6 The options are specified on the command line after the relevant processor executable and can be used in combination with each other. An example of the syntax for running the Batch Processor with multiple command line options is as follows:

"c:\Program Files\AIRE\bin\AIREBatchProcessor" -project C:\models\data\Emissions_Model\aire-project.epp -output C:\temp\output.txt

3.10.7 This would run the Batch Processor using the model and settings in the specified file (aire-project.epp) and would write the command prompt messages to the specified output file (output.txt).


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APPENDIX A: Input and Output File Formats


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Input and Output File Formats

The formats of the various files associated with AIRE are outlined in this Appendix.

Input filename: trips-ALL.csv

Output filename: trips-ALL-AIRE.csv

Column Heading Description

Tag Number Unique vehicle ID numberPath Path name for vehicles assigned to a fixed path or

'nopath' where vehicle is assigned from the demand matrices

From Zone Origin zone of vehicleTo Zone Destination zone of vehicleVehicle Type Type of vehicle (from list defined in each model)Base Vehicle Type † PEARS base vehicle typeDistance (m) Distance travelledDeparture Time (HH:MM:SS) Trip departure time in HH:MM:SS formatDeparture Time (s) Trip departure time in secondsArrival Time (HH:MM:SS) Trip arrival time in HH:MM:SS formatArrival Time (s) Trip arrival time in secondsTime Taken (HH:MM:SS) Journey time of trip in HH:MM:SS formatTime Taken (s) Journey time of trip in secondsFuel Type * Fuel typeFuel (ml) Fuel usedNOx * Calculated NOx for trip in milligramsPM10 (mg) * Calculated PM10s for trip in milligramsTotal Carbon (mg) * Calculated Carbon for trip in milligramsMean Time (HH:MM:SS) † Measure of mean journey time for the ODVehicle Characteristics ** Vehicle & fuel type, EURO class and load assigned by

AIRE

* Denotes columns modified by AIRE** Denotes column added by AIRE† Numerical values not used in AIRE


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Input filename: busdelay.csv

Output filename: busdelay-AIRE.csv


Tag Number Unique vehicle ID numberRoute Name of PT routeStart Time (HH:MM:SS) Start time of PT vehicle in HH:MM:SS formatStart Time (s) Start time of PT vehicle in secondsEnd Time (HH:MM:SS) End time of PT vehicle in HH:MM:SS formatEnd Time (s) End time of PT vehicle in secondsTime Taken (HH:MM:SS) Journey time of trip in HH:MM:SS formatTime Taken (s) Journey time of trip in secondsDistance (m) Distance travelledFuel Type * Fuel typeFuel (ml) Fuel usedNOx * Calculated NOx for trip in milligramsPM10 (mg) * Calculated PM10s for trip in milligramsTotal Carbon (mg) * Calculated Carbon for trip in milligramsLast Stop Name of last stop usedRelative Departure Time (HH:HH:SS) Departure time from stop relative to start of journeyVehicle Characteristics ** Vehicle & fuel type, EURO class and load assigned by

AIRE

* Denotes columns modified by AIRE** Denotes column added by AIRENote: stop and relative departure time columns are repeated for all stops on route


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Input filename: carpositionsNNNNNN.csv

Output filename: carpositionsNNNNNN.csv


Timestamp Simulation time, seconds since start of weekLink Location of vehicleTag Number Unique vehicle ID number

Base Type † PEARS base vehicle typeVehicle Type Type of vehicle (from list defined in each model)Section Number Vehicle section (always 1 if not articulated)PosX (m) Model X co-ordinate of vehiclePosY (m) Model Y co-ordinate of vehiclePosZ (m) Model Z co-ordinate of vehicleBearing (deg from N) Direction vehicle is travellingElevation (deg) Angle of elevation of the vehicle/sectionGradient (%) Coded link gradientAcceleration (mpss) Vehicle acceleration in this timestepSpeed (mph) Vehicle speed in this timestepAngular Velocity (deg/sec) Rate of change of bearingBrake 1 if vehicle is braking, 0 if notRight Indicator 1 if indicating right, 0 if notLeft Indicator 1 if indicating left, 0 if notBusboard Blank or bus route number if vehicle is a busNOx * Calculated NOx for timestep in milligramsPM10 (mg) * Calculated PM10s for timestep in milligramsTotal Carbon (mg) * Calculated Carbon for timestep in milligrams

* Denotes columns added/modified by AIRE

† Numerical values not used in AIRE

Input filename: N/A

Output filename: emissions_link_summary.csv


Link Network link reference (Anode:Bnode)Vehicle Type Type of vehicle (from list defined in each model)Fuel Type Fuel type for this vehicle typeNOx Calculated NOx for link in milligramsPM10 (mg) Calculated PM10s for link in milligramsTotal Carbon (mg) Calculated Carbon for link in milligrams

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