Build Selected Link Trip Table

This section discusses the process involved in incorporating the selected link trip table to the centroids in MapInfo. This step can be useful to determine the zonal origins and destinations for the interchange and assist in identifying the impact area for the interchange (local, regional or over the entire network).

We will continue to use the same interchange as in the selected link analysis



and focus on the same ramp.



The goal of building the selected link trip table is to determine what zones are responsible for the traffic which uses either the ramp of the interchange and provide a method to determine, for a specific zone, where the trip which use the ramp or interchange are heading. The control file used is the same as that for the selected link analysis, however, the final step of loading the selected trip table doesn't need to be applied. An example is provided.


$LOAD HIGHWAY SELECTED LINKS
$FILES
    INPUT FILE = HWYNET, USER ID =$NET90X.BIN$
    INPUT FILE = HWYTRIP, USER ID =$TOT90X.TRP$
    OUTPUT FILE = LODHIST, USER ID =$TOTAL.BIN$
    OUTPUT FILE = SELHIST, USER ID =$SELHIST.BIN$
$HEADERS
    'RUN FOR SELECT LINK ANALYSIS'
            'USING'
    'LOAD HIGHWAY SELECTED LINKS'
$OPTIONS
$PARAMETERS
    IMPEDANCE = TIME 1
    LOAD SELECTED LINKS = 492-493
    ONE WAY SELECTED LINKS = 492-493
$END TP FUNCTION

$BUILD SELECTED LINK TRIP TABLE
$FILES
    INPUT FILE = HWYTRIP, USER ID =$TOT90X.TRP$
    INPUT FILE = SELHIST, USER ID =$SELHIST.BIN$
    OUTPUT FILE = SELVOL, USER ID = $SELOUT.BIN$
$HEADERS
    'RUN FOR SELECT LINK ANALYSIS'
            'USING'
    'BUILD SELECTED LINK TRIP TABLE'
$OPTIONS
    OR LINKS
    PRINT TRIP ENDS
$PARAMETERS
    SELECTED LINKS = 492-493
    SELECTED PURPOSE = 1

Running this control file through Tranplan will develop the SELOUT.BIN file which contains the trip table. As this file is binary, the Tranplan Utility TPCARD1 will convert this binary file into a text file. The file created by this operation can be open directly in MapInfo as a text file with space delimitation. The file contains the origin zone, destination zone and number of trip that travel between the two zones. This is shown in MapInfo (note that column headings have been added to help identify the information).



With this information, the user can begin to develop different visualization images of the network to show how traffic uses the ramp or interchange. For example, joining the trip table to the zones for zone 11 (select from the trips table all records with a origin zone of 11, save this information to a new table and join based on the destination zone). The select link analysis shows a similar graphic with the interchange location clearly highlighted for a reference.



Another visualization tool is to show all the origins graduated with respect to the total number of trips from each origin. Note that the same type of image can be developed for the destinations.



This information should be developed and compared for the different interchange locations and alternatives proposed for the area. Another important item to remember is that in the information shown will be based on the time scale entered during the Tranplan run, probably a 24-hour basis.

     Select any of the options to receive more information or click on the back button to return to the GIS analysis page or the site map button to go to the site map.