For an intermodal transport network model, I want to include restrictions to the type of ships (size) that can navigate through certain waterways. I want the model to calculate the lowest cost for routes that might have smaller ships, but that can navigate through the whole waterway or might have large ships on large waterways with transshipment to smaller ships for smaller waterways. At this moment, I included different networks for each waterway. These are connected via harbor nodes were transshipment can take place. I want to know if it is also possible to use a single network dataset for all ship sizes and restrictions specific per ship type. I don???t know how to deal with it as transshipment is required between ships. It cannot simply add the segmented cost of small and big ships, but has to decide whether it is cheaper to take the small ship for the whole route, or if the cost for transshipment pays off against economies of scale for a larger ship combined with a smaller ship.
This is possible in two ways: Manual and a 3d analysis (if i understand your question correctly) !!
Do you have many possible OD movements ? Or do you have just a few ? There is a manual way to do it if it is few, but if it is many, I am not sure how ( i havent tried it, but should be possible with programming). With no programming, unfortunately it is a manual process.
I also work on freight movements, may I ask what is the final objective of the study ?