It will mean that part of the road linking Brightons and Polmont will be closed for two weeks and diversions are in place.
The work, which is expected to last around two weeks - weather permitting - will see a new 22m steel structure weighing 20 tonnes installed at a cost of £133k.
The new bridge will have a new protective paint system which they say will allow it to stand up better to the elements.
Councillor Paul Garner, Falkirk Council's spokesperson for the environment said: “The existing bridge was beginning to show its age and in future, will require less maintenance reducing costs for us.
“It’s popular with local residents and we hope that the two-week closure while the work is carried out isn’t too disruptive.”