With three deaths already on open roads this week, the roads policing unit is issuing an urgent appeal to riders and motorists to take extra care.
They say that means travelling at the right speed for the road conditions and riding within your own ability.
Inspector Terry Stephen says the recent warm weather has probably tempted more riders than normal to go out for a lap.
And he's stressing that roads around the course can still be busy with traffic first thing in the morning.
Vote on Castle Rushen High School funding 'very unlikely' before election
It had previously been hoped Tynwald would consider the plans in June
Ramsey Commissioners to host public meeting about cottage hospital
Commissioner Juan McGuinness says residents deserve 'clarity' about ongoing situation
DfE provided more than £250,000 to MT to assist with below ground fibre installations
Minister says figure was to ensure premises deemed not commercially viable could be included in rollout
Man given suspended sentence after importing 2kg of cannabis to Island
37-year-old was found guilty at trial