A section of the TT course closed to through traffic between Glen Auldyn and the Ginger Hall in Sulby this morning.
Through traffic is being diverted via Bowring Road, Jurby Road and St Judes Road.
A post by Highway Services said: “Many of the areas to be improved straddle the centre-line of the road and so reducing the space available to safely pass the resurfacing team.”
The closure, which will remain in place 24 hours a day until no later than 3.30pm on Friday April 24, is also being used to extend the carriageway drainage system at Kerrowmoar.
TT preparation work, including black and white kerb painting, is being undertaken during the closure.
Highway Services confirmed: “Painting the kerbs during this closure should allow the contractor to expedite these works”.
Vehicular access to and from addresses within the closure area will be maintained, although delays may be expected due to multiple work sites.
Bus Vannin services will generally follow the diversion. The only exceptions will be the school buses, which will be marshalled through the works at the start and end of the school day.