The Isle of Man's Mountain Road has been converted to a one-way route for the duration of the TT races.
The one-way system is now in effect from Ramsey Hairpin to the Creg-ny-Baa and will remain that way until the TT festival is over on 14 June.
It was introduced for the 2007 TT races as a safety measure to reduce the likelihood of head-on collisions on the road.
The road was closed for several hours on Saturday while signs were put up.
The work was hampered by the bad weather and had to be extended throughout the afternoon.
Practice week continues from Monday until the races begin on Saturday with the Superbike TT Race.
The last race will be the Senior TT which takes place on 11 June.