Definition of "underbridge"

As to underbridges, the policy is to wait until the small underline bridges become due for renewal when they will be replaced by prestressed concrete structures.

1979 August, Michael Harris, “A line for all reasons: the North Yorkshire Moors Railway”, in Railway World, page 412

Additionally, NR has been given permission to alter highway rights at the underbridge at Littleport station.

2020 December 2, “Network News: Green light for NR to close crossings”, in Rail, page 23