With student Dave Jones at the wheel, the 57-year-old double-decker and its original diesel engine came to the end of the line in regular transit service, first in London and then in Davis. No other bus of its kind in the world has lasted as long on the original engine, said Anthony Palmere, Unitrans assistant general manager. Now, in order to use No. 1014 in regular service, the transit system must outfit the bus with a cleaner-burning engine. Otherwise, Unitrans will keep the bus in its original, historic condition and use it for special occasions, such as the Picnic Day Parade. Unitrans has five other double-deckers, two converted to compressed natural gas, two with new diesel engines and the fifth getting a new diesel engine. All of the double-deckers came from London, with the first two arriving in 1967. During regular transit duty in London and Davis, No. 1014's engine racked up more than 1.25 million miles of service. That equals 50 trips around the world, or 118 round trips between London and Davis. Inside: Student employee Andrea Nutt was the conductor aboard Unitrans bus No. 1014 when it made history on Dec. 14.