Interchange Development with a Model

Developing an interchange with an existing model involves two distinct tasks. The first is the modification of the network infrastructure to represent to the interchange and the second is the modification of the socio-economic characteristics of the area to reflect changes in development due to the interchange.

For the network changes, these can either be done using the Tranplan-GIS environment or can be performed in HNIS or through modification of text files. If the user is operating with the Tranplan network in MapInfo GIS, a MapBasic program has been written to assist in the updating of the network to represent the interchange. The program allows the user to digitize new nodes and links to represent the interchange location and then automates the process of updating coordinate values, node numbering, distance calculations and enters default speeds and capacities.

This program can be very useful as the policy considerations indicate that all feasible alternative without and different alternative with the interchange need to be examined. A recommendation is to develop each alternative as a separate directory where the modeling is performed. This will help structure the model runs and help avoid potential losses in results or confusion about which results are for which alternative.

As for the socio-economic modification to the network, the user needs to change the productions and attractions around the new interchange to accurately reflect the amount of development that is expected to occur in the area as a function of the new interchange. This step is very important because one of the policy considerations looks at making sure that the land-use entered for the alternatives is reasonable.

At this point, the user can either continue and examine the GIS-Traplan analysis or the HCS analysis.

        

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