Thousands of visitors are on the Isle of Man for the first day of the TT festival.
The event gets under way on Monday evening with its first practice session leaving from the TT Grandstand in Douglas at about 1820 BST.
The Mountain course, which celebrates 100 years of racing this year, will be closed to allow the racers to practise.
Last year, about 10,300 motorcyclists travelled to the event, which runs for two weeks from 30 May until 10 June.
The Mountain section of the course will close at 1700 BST with the rest of the 37.7-mile circuit closing by 1800 BST.
The course is expected to start reopening no later than 2130 BST, with the Mountain section open an hour later.
A one-way system has been introduced on the Mountain road for the duration of the festival and there will be an increased police presence on the roads to help keep riders safe.