North Carolina General Statutes Chapter 136. Transportation § 136-20.1. To require installation and maintenance of block system and safety devices; automatic signals at railroad intersections

(a) The Department of Transportation is empowered and directed to require any railroad company to install and put in operation and maintain upon the whole or any part of its road a block system of telegraphy or any other reasonable safety device, but no railroad company shall be required to install a block system upon any part of its road unless at least eight trains each way per day are operated on that part.

(b) The Department of Transportation is empowered and directed to require, when public safety demands, where two or more railroads cross each other at a common grade, or any railroad crosses any stream or harbor by means of a bridge, to install and maintain such a system of interlocking or automatic signals as will render it safe for engines and trains to pass over such crossings or bridge without stopping, and to apportion the cost of installation and maintenance between said railroads as may be just and proper.