Urgent repairs are needed to Ballagawne Bridge near Kirk Michael.
The Department of Transport has discovered corrosion on the iron girders which support the structure, on the Kirk Michel to Peel Road.
No major work has been carried out on the bridge since it was built, to carry traffic over the old Kirk Michel to St John's railway line.
Extra supports will be installed on either side over the next two weeks, with traffic directed over the centre of the bridge to avoid the weakened area.
"It's just the way of the world now": Manx businesses face dilemma amidst rising costs and online competitors
'Multiple factors' seeing businesses close or change hands
Breast Cancer Now seeks volunteers for latest 'sleep out' challenge
July's event taking place at Sea Lion Rocks at Groudle Glen
Isle of Man Beer and Cider Festival returns
Popular CAMRA event is in its 13th year
Future of North Barrule triskelion to be decided by planning
Manx Utilities wants to clarify the planning status of the feature
