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 Cleveland, Yorkshire and Durham are frequently used, such as the continued existence of Cleveland Police and Cleveland Fire and Rescue Service, and of the Cleveland postal county. The Teesside Built-up Area (BUA), previously the Teesside Urban Area, identified by the ONS for statistical purposes had a population of around 376,633 according to the 2011 census which is up 3% on the 2001 figure of 365,323, and had the following subdivisions: Eaglescliffe and Yarm are counted as a separate Yarm urban area, separated by a narrow gap, which had a population of 19,184 according to the 2011 census up 5% from