Pulrose Bridge in Douglas is set to close for 12 months from March 2021.
It's whilst a £3.4m project is underway to replace the bridge - designed to reduce the risk of flooding and protect 'vital infrastructure connections'.
The current structure was built in 1931, the DOI says it's no longer practical nor economically justifiable to extend its life further.
As witnessed in 2015, the River Douglas is susceptible to flooding - the department says new reinforced concrete and steel beam structures will significantly reduce this risk.
The bridge will also feature cycle lanes on both sides, linking Peel Road with the Heritage Trail and Nunnery cycle routes.
Pedestrian access between Peel Road and Pulrose will be maintained, while traffic will be diverted.
Crogga still owes the Isle of Man Government money
DoI says works at Liverpool ferry terminal will take longer
Over 50 employment tribunals outstanding at the DoI
Free period products bill raises cost concerns for MHKs
Key road in Ramsey to re-open early this afternoon
Want to start training to become a nurse?
Appeal launched after fly-tipper filmed dumping rubbish
Prepare your pets for Bonfire Night, says Manx charity
