Possible Clues:

• Efficiency improvers
• Quicker routes
• Timesavers ... or the starts of 17-, 26-, 36- and 51-Across?
• The fast ways of the skinheads?
• Drivers' local knowledge
• Routes that are quicker than the normal ones
• Quicker ways of getting spirits down?
• They're more direct if they're the crew, perhaps
• Labour-saving schemes welcomed by barbers?
• Bob's known for the quick way of doing things