The Mountain Road is one way from Ramsey to Douglas for the duration of TT fortnight.
It was introduced at the Centenary TT in 2007, to try and eradicate head-on collisions.
Inspector Terry Stephen of the Roads Policing Unit says despite the change, people still need to drive and ride responsibly up there:
Weather warning for gales coming into force tomorrow
Gusts of up to 55mph possible, forecasters warn
People urged to take care when exploring the Island
Fire service issue advice after dog rescued from the Chasms
TT 2025: Triple-header of opening racing planned for tomorrow
Evening contingency session also available if required
Nearly £10k raised to help cover teen's funeral costs
Hopes to 'provide some comfort to Christopher’s family at this very difficult time'
Richard Hammond makes first visit to Isle of Man TT
Renowned motoring presenter and journalist led out today's legacy lap