Some bridges were widened when the line between Penruddock and Threlkeld was converted from single track to double track to cope with heavier than expetced freight traffic.

All bridges between Penrith and Braithwaite (west of Keswick) were strengthened in the 1930s to main line standards.

All structures which join, carry or cross public rights of way are maintained by Local Authorities.

The two main viaducts and a few other structures are still the responsibilty of the Railway Industry. 

The bridges on the Path from Keswick to Threlkeld are maintained by the Lake District National Park Authority. Their apprenticeship schemes  now include training in bridge maintenance.

Other structures ae the responsibility of individual landowners.

A few have been removed where they restricted the height of vehicles on busy roads, or are no longer required.

All significant structures required remain in place.

A few new structures will be required, but this is little more than normal developments changes would have taken place over the ars as land use changed and roads developed.

"Infilling" bridges

At some stage all bridges need major repairs to ensure their strength to carry future traffic. Sometimes a decision is made to "infill" a bridge rather than carry out detailed repairs.

"Infilling" means building a bank of stone or earth under the bridge and casting a concrete "bed" under the bride deck to support it.

That process reduces future maintenance needs, but completely blocks the space under the bridge.

If a bridge over a railway trackbed has been "infilled", when the railway is re-opened, all the concrete and earth or stone has to be dug out and the bridge deck replaced. That will probably cost much more than the repairs required when the decision to "infill" was made.

The Lake District National Park Authority rejected an application to "infill" a ridge early in 2013, having told the applicant that such action would contravene policies to protect the route for future sustainable transport use.