As the line gained popularity, its reach and infrastructure were significantly upgraded:
: The project saw the reopening of Five Ways station and the construction of new stations like University and Longbridge to serve the expanding city. Birmingham Cross City Line
: Initially, services utilized refurbished Class 116 Diesel Multiple Units . 2. Expansion and Modernization (1980s–1990s) As the line gained popularity, its reach and
The concept for a unified line began in 1970 when the newly formed sought to integrate local rail services. The project, approved in 1971 and officially opened on May 8, 1978 , merged existing tracks into a single through-service: : It linked Four Oaks in the north
: Services reached Redditch in 1980, eventually increasing from hourly to half-hourly due to high demand.
: On November 28, 1988, the line was extended to Lichfield Trent Valley .
: It linked Four Oaks in the north to Longbridge in the south via Birmingham New Street .