Other motor bus routes quickly developed from Chester-le-Street, its central location being ideal for other towns and colliery villages nearby.

Northern even built the bus station in Durham (as a terminus) before Tilling's United Automobile Services arrived there.

Throughout the 1930s smaller independents were bought out and British Electric Tracton in the North East began to convert to motor bus operation, expanding into Sunderland and North Tyneside taking over the declining tramway routes and expanding the bus routes further.

By now Northern even built their own buses to accommodate the high passenger numbers with the very low bridges in the area (meaning three-axle single deckers).

In the 1950s Northern bought up more smaller bus operators and with expanding industry at the time rebodied quite a few of their prewar buses.

Northern placed a large order for Bristol VRs with Eastern Coach Works and Willowbrook bodywork in 1977 to replace them.