Possible Clues:

• '59 Kingston Trio hit
• Kingston Trio classic
• L.A. bus co.
• N.Y. commuter org.
• Los Angeles commuter org
• 1959 hit that was a 1948 political campaign song
• NYC subway manager
• N.Y.C. bus insignia
• NYC subway org. whose 'M' stands for 'metropolitan'
• Trio