I'd go with Marylebone (and Chiltern in general.)
Whilst it's still not back to pre-Covid levels, over the course of thirty years it went from being threatened with closure and just having services to High Wycombe and Aylesbury and an infrequent service to Banbury to having half hourly services to Birmingham and Oxford, and direct services to Stratford-on-Avon.
Not bad for a railway that's only double track for most of its length.
Whilst it's still not back to pre-Covid levels, over the course of thirty years it went from being threatened with closure and just having services to High Wycombe and Aylesbury and an infrequent service to Banbury to having half hourly services to Birmingham and Oxford, and direct services to Stratford-on-Avon.
Not bad for a railway that's only double track for most of its length.


