It has repeatedly been noted that there is a clear logic behind the geographical expansion of transport networks. That implies that one can model how those transport networks expand geographically; and how the final network would change if the network is constructed with different objectives.
In the last years I have developed the so-called Transport Link Scanner model, which is a GeoDMS based tool that allows the exploration of the effects of economic context and policy preferences on transport network expansion. The model combines a conditional logit model, some heuristics and techniques from the literature on corridor location problems and transport modelling methods to simulate the most likely network after the introduction of a new transport innovation.
The most recent version of Transport Link Scanner can be downloaded through this page. The scripts are downloadable here. The data is available here. Instructions to get you started are available here.