From the 1974 merger of Sheffield, Rotherham and Doncaster municipal bus companies until the mid-1990s, the operating area of South Yorkshire was split between South Yorkshire Transport and Yorkshire Traction with the former dominating Sheffield and Rotherham.
From the 1974 combination of Sheffield, Rotherham and Doncaster municipal bus companies until the mid-1990s, the operational zone of South Yorkshire was split between South Yorkshire Transport and Yorkshire Traction with the former controlling Sheffield and Rotherham.