Sentence:  At this time of crisis in our Nation 's <WSD>commuter</WSD> railroads , a new threat to the continued operations of the New York Central has appeared in the form of the Chesapeake + Ohio Railroad 's proposal for control of the Baltimore + Ohio railroads . 
Meaning of the word marked with <WSD> tags:  a passenger train that is ridden primarily by passengers who travel regularly from one place to another