Proposals as part of the original electrification work in the early 1970s[4] envisaged a new underpass here and land was set aside for its construction.

This means the entire embankment is covered in red poppies during their flowering season giving the name to the location 'Poppy Bank'.

Although this routing skirts around the flat junction in a curve that takes trains over a physically longer distance, it removes the need for them to dwell at Hitchin – sometimes for several minutes – awaiting a path across the tracks of the main London–Peterborough route, thus decreasing the overall journey time to Cambridge in many instances.

The scheme improves the punctuality and reliability of both the London–Cambridge and London–Peterborough routes, the latter because Peterborough-bound stopping trains are no longer delayed if running closely behind a Cambridge service being held at Hitchin waiting to cross the flat junction.

By January 2015 the only form of traction not to have used the flyover was electric locomotives (regular services are electric multiple units); Union of South Africa became the first steam locomotive on the flyover when it moved empty coaching stock to Cambridge in preparation for a tour to York.