County Borough of Teesside councils in 1918, and was a pioneer operator of electric trolleybuses. The three undertakings adopted a common livery of turquoise and cream in 1967 in preparation for their amalgamation. On 1 April 1968 the combined fleet became Teesside Municipal Transport. Teesside initially operated a mixed fleet of trolleybuses and omnibuses, but on 4 April 1971 trolleybus operation ended. A formal closure ceremony was held two weeks later. Before 1968 the Teesside area was served by three police forces: Middlesbrough Borough Police, Durham Constabulary and the North Riding of Yorkshire Constabulary. It was originally envisaged that the new county borough would
Teesside Airport railway station South Junction; it was opened by British Rail on 3 October 1971. There are two platforms, each long enough for a four-coach train. The airport changed its name to Durham Tees Valley Airport in 2004, however, the station's name was not updated. In 2007, the train operating company Northern erected new signs reading "Teesside Airport", replacing previous signs which had used a hyphen in "Tees-side". National Rail now also lists the station as "Teesside Airport". In December 2017 it was announced by Durham Tees Valley Airport (DTVA) that the footbridge and eastbound platform would be closed to save DTVA having