Sentence:  At the head of the Rebel column is the <WSD>road captain</WSD>, who acts as the chief executive while the club is on the road. He sets the speed at which the club travels. The <WSD>road captain</WSD> must have a sound knowledge of how the members' hogs will perform under varying road conditions and be able to coordinate long bike formations that may stretch out for a half-mile. 
Meaning of the word marked with <WSD> tags:  An experienced rider who organizes and marshals the motorcycle club on the road.