About Dual Gauge, from BoardGameGeek:
The title Dual Gauge refers to the fact that there are two kinds of track - standard gauge and narrow. Standard is more expensive and more efficient, while narrow gauge is cheaper and rather inefficient. These rectangular track tiles are laid across adjacent hexsides, and all companies are able to utilize a shared track network provided they are connected to it. Different types of track will of course call for different types of trains. Stock purchases put funds in the company coffers, and the company uses this money to pay for track. Trains, on the other hand, are paid for in stock value itself. Those trains can also be "rusted" by the purchase of newer models. Companies can also "token" station spaces on the map, increasing their routes while potentially blocking access for rivals. These, too, are paid for in stock value, by decreasing that value by an entire row in the game's capricious two-dimensional stock market.
This is not only a game, but a game system played on multiple maps. Each map has unique twists, and a set of companies with unique asymmetric abilities. This base set gets the party started with two maps. Portugal is intended as an introduction to the system, but asks players to contend with difficult mountainous terrain. The challenging Detroit map, set in part of Michigan's Lower Peninsula, finds players taking on debt to keep underfunded railroads afloat, all with an eye toward reaching Chicago and its double-route bonus.
-description from the publisher
