The Mountain Road will close for 10 days from Tuesday April 7 to allow for TT prep and maintenance works.
The DoI has confirmed the route will be shut in sections from 9.30am on April 7 until 3.30pm on Friday April 17. The closure will be in place from the Creg Ny Baa to the Bungalow and from the Bungalow to Ramsey.
A 24/7 access corridor will be maintained between Bungalow Bridge and the Victory Café however the Beinn Y Phott Road junction will not be available.
The programme of works includes the installation of poles and signs for the TT one-way system, safety equipment, and marshalling posts.
Cyclical maintenance such as gully cleaning and verge cutting will also be carried out, alongside paver resurfacing and re-lining at several locations.
Further repairs will address surface patches and the reconstruction of damaged roadside walls at the Gooseneck Waterworks and the Hairpin.
In addition, contractors for the DoI will fell more than 20 dead or dying ash and elm trees between Stella Maris in Ramsey and Ballure Waterworks.
Highway Services noted that some planned activity, particularly resurfacing, is weather dependent so provision has been made to extend the closure up to 3.30pm on Thursday April 23.