A Roads and Maritime Services spokesperson said while many students may not return to school until Monday, the first gazetted school day is today - and double demerits will be in force.

"Some schools will be closed today, but other schools may be open," the spokesperson said.

"School zones operate on all gazetted school days to ensure the safety of students who may be travelling to or from school.

"Not all motorists will know if the school they are driving past is having a pupil-free day or if students are at school.

"This is why all 40km/h school zones are consistently applied and will be in force from the first gazetted school day of term one.

"Motorists need to be aware of school holiday gazetted dates, especially during double demerit periods, to ensure they keep within the legal speed limit and don't get caught speeding and run the risk of losing their licence."