Brickwork on the Worston Lane bridge, north of Stafford, was badly damaged yesterday (14 February).
Work took place throughout last night to carry out repairs and make the bridge safe.
The line fully reopened just before 3pm today (15 February).
Network Rail is working with the police to trace the driver who failed to stop at the scene.
Martin Colmey, current operations manager for Network Rail, said: “We worked through the night to make the bridge safe so trains could continue to run. We made ongoing repairs today so we could fully reopen as quickly as possible without any speed restrictions.
“The bridge did what it was designed to do and prevented a potential major incident of a lorry crashing onto the railway. However, it is hugely frustrating as the incident was entirely avoidable. Thousands of passengers have been disrupted as a result of this driver not driving responsibly or carefully.”
Passengers are advised to plan and check their journeys at www.nationalrail.co.uk.