Peter James Field was born in 1951 and took a degree in Chemistry at the University of Leeds before joining a British Rail training scheme on the Birmingham Division in 1972. He became Assistant Station Manager for Liverpool Street in 1973. He then moved into area management, becoming the Area Operations Manager at Broxbourne, Area Manager at Southend in 1979, as well as at Stratford before becoming Area Manager at London Bridge in 1984. He became Network Director Eastern at Liverpool Street in 1986, moving in 1989 to be Operations Manager for British Rail: Southern Region.

Between 1991 and 1996, he served as Director for Network SouthEast South Western Division, the South West train operating unit and the South West Trains train operating company. He then became a Consultant for Steer Davies Gleave Consultancy in 1996. He has also served as Rail Strategy Director for Transport for London, leaving that post in 2009.