Two-Mode 4-Stage Model
The Four-stage procedure will run your input data trip ends through a distribution model, which will split the trips into their individual links, and the Mode choice model will split these trips into their respective modes on each link. The Four-stage process will run both of these models. You need to click on ‘Models‘ and then go down and click on Two Mode Four Stage. The Four-stage run will run the distribution and the mode choice models of the software.
You will then be presented with a series of windows with spaces to fill in the input and output files.
Each sheet on this window needs to be completely filled with the names of the respective files. The files you are inputting will sometimes be separated into a number of different market segments such as Car available work, car available other and non-car available. If you enter the correct number of market segments on the General Options tab (more on this later) then it will automatically search for these different files in the input boxes. It is only necessary to input one of the market segment files into the windows and have the other market segment files in the same directory. The following files go in the following spaces:
In the Input Matrix Files sheet:
- Base Year AM Peak Hour Car Trip Matrix: - ‘OneHourObservedBaseTripMx.csv’
- Base Year AM Peak Hour HGV Vehicle Matrix: - ‘OneHourMxHGVAm.csv’
- Base Year 24 Hour HGV Observed All Passengers All Mode Trip Matrix: - ‘AllDayObservedBaseTripMx.csv’
- Car 24 Hour To AM Peak Factor Matrix: - ‘CarDay24HrFactorMxAm.csv’
In all of these the Market Segment is 1 as none of these files are Binary ERICA. If they are you should enter the respective Market segment for the data.
The input coefficient files are as follows.
- Distribution: - ‘CoefDistrib.pdo’
- Mode Choice: - ‘CoeffMchoi.pdo’
- Coefficient File for Four Stage Model: - ‘Coeff4stage.pdo’
In the Other Input Files:
- Distribution Indicator Matrix that shows which Coefficients to use for each Matrix Cell: - ‘Indicator.csv’
- Distribution Switch Matrix (-2, -1, 0, >1): - ‘Switch.csv’
- Forecast Year Trip Ends: - ‘ForecastTripends.csv’
In the Output Files sheet you can name these files as you want and put them in any directory. It will also write some files into the input files directory and so it is a good idea to write them into this same directory. The standard names that are used are as follows (It is not necessary to name them anything in particular but it can be easier to name them something related and they have to be in the correct format):
- Base Year 24 Hour Synthesised All Passengers All mode Trip Matrix: - ‘1.csv’
- Road Vehicle AM Peak Matrix: - ‘2.csv’
- Road Vehicle InterPeak Matrix: - ‘3.csv’
- Public Transport 12 Hour Passenger Trip Matrix: - ‘4.csv’
- AM Peak Hour Assignment: - ‘5.csv’
- Road Vehicle Interpeak Hour Assignment: - ‘6.csv’
- Public Transport 12 Hour Passenger Assignmment: - ‘7.csv’
Then you need to go into the General Options tab where you can then select the number of runs the program goes through and therefore the number of iterations of each file you will get in the Number of major iterations for 4 stage process box. A standard number here is normally 4 as this number is usually sufficient for the values to settle, but you can enter as many or as few as you like. In this window you also need to fill in a Run directory where the files will be output. This directory has to contain a copy of the file ‘ParkingZonesMx.csv’. In this window you also need to enter the number of market segments that the model is using.
You then need to go into the options window at the bottom and then onto the General tab to enter the number of zones in your model. Then on the Assignment tab you need to select the Car mode (car) and Walk mode (walk). Once you have completed the options part of the form you click OK and this will bring you back to the four stage model.
You then click on Run in order to run the data and get the output files.
In the files that the software outputs there is an error-log file called ‘pd-ModelLogfile.dat‘ that explains exactly what the program is doing and the run of the software. This will be output along with the rest of the files in the respective directories.
The log file will be displayed so that you can see the assignments running and how the flows on links are changing after each capacity restraint iteration. You should be able to see the changes in flow converging to zero.
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