An important area of railroad history that seems often to be overlooked is the history of the  railroad geography, infrastructure, and traffic flows that provided the raison d'être of the railroad lines in the first place.

These pages provide both current and historical route descriptions, infrastructure descriptions and data for places along those routes, and traffic descriptions and data for those routes.

Major Traffic Flows

Route histories and descriptions can be accessed from the histories of the traffic flows for the major types of traffic:

Freight Traffic Flows

Passenger Traffic Flows

The history of individual routes is complemented by the Comparative Capacity of Parallel Routes over the decades.

Train Control and Signaling

An important overlay on the route infrastructure and traffic flow descriptions is the history of train and traffic control, and signaling along these routes.

Direct Access to Route Descriptions

For access purposes, the routes have been divided into those within Regions having a complex network of lines, both local and those which provide segments of Trunk Routes, and those which form part of the trunk routes carrying traffic from one part of the North American Continent to another. Where a route segment falls into both categories, the descriptions in the Trunk Routes category are usually at a lower level of detail than those in the Regions category: