Alan Williams was appointed to produce the first temporary commission, called "Sidetrack", which portrays the ordinary and extraordinary sights, often unfamiliar to passengers, on the system and was displayed throughout the network.
Alan Williams blev udpeget til at producere det første midlertidige værk, kaldet "Sidetrack", som forestiller ordinære og ekstraordinære steder i systemet, der ofte er ukendte for passagerer, hvilket blev vist gennem netværket.