What characterizes a short line railroad?

A short line railroad is characterized by its role in connecting smaller towns and local industries to larger national rail networks. This is important because short lines serve as critical links in the transportation infrastructure, facilitating the movement of goods from smaller, often rural areas to major distribution hubs. They typically operate over shorter distances and focus on the needs of local businesses, which may not have direct access to larger rail services.

By connecting these areas to broader rail networks, short lines help stimulate local economies and provide essential services for industries that require freight transport but may not have enough volume to warrant service from larger carriers. This makes option C the correct choice, as it accurately reflects the primary function and significance of short line railroads.