Catseyes being installed on the New Castletown Road will mean a series of daytime road closures from next week.
The DOI says work will start on Tuesday, May 6 on the stretch between Glashen Hill roundabout and Orrisdale Road.
That section will shut at 9.30am until 3.30pm.
The department says it hopes to finish the entire road by Friday 16 May.
Two more schemes backed by government fund
Island to get Bikesafe scheme for first time
Jurby Junk's Stella dies aged 90
No plans to publish UK's assisted dying letters
Burst water main disrupts Onchan supply
Government advice following spike in data breaches
Plans for four-foot flood walls at Ramsey harbour
Garage blaze in the early hours of this morning