Despite the gradual modernisation of the carriages, the use of railways for transporting mail drastically declined towards the end of the 20th century. In 1988, a radical Travelling Post Office review was introduced which meant the reduction, re-routing and removal of numerous TPOs. This left only 35 in service, and by 1994 this was just 24. The last TPO services ran on the night of 9 January 2004.