There are an estimated 70,000 railroad track miles in North America that are non-signaled lines otherwise known as “Dark Territory”. Operating in Dark Territory is a reality for Class I railroads as well as for the hundreds of other regional and short-line carriers. Dark Territory poses many challenges to safety and efficiency.
For example, track switching from the mainline to a siding traditionally meant brining the train to a complete stop, personnel exiting the locomotive, manually throwing the switch into reverse, bringing the train through the siding, and finally stopping again to return the switch to the normal position.