Sentence:  This includes plans to run earlier <small>[Sunday]</small> services on the Derby to Crewe and Skegness routes, which will require Network Rail to open <WSD>signal boxes</WSD> on these lines earlier than at present. 
Meaning of the word marked with <WSD> tags:  A building, typically adjacent to or spanning a railway line, from where signals, points and (sometimes) level crossings are controlled.