Hundreds of thousands of kids are going back to school Tuesday, some for the very first time, as police warn motorists to take an extra moment for all the additional pedestrians and cyclists on the roads this morning.

All four public school boards operating in Toronto and the GTA get underway Tuesday morning, with 250,000 kids from kindergarten to grade 12 heading to class in Toronto alone.

All those kids on the move mean additional traffic.

“All road users need to consider the safety of our most vulnerable users – school children, pedestrians, and cyclists, when they are travelling on our roads,” Toronto police said Tuesday.

They say they are on the lookout this week for drivers who park illegally, speed, use their phones or behave aggressively around schools.

“This campaign is about ‘no tolerance’ for violations, but also about asking you to commit to changing bad driving habits,” police say.

GO Transit and the TTC both ask commuters to take extra time when out on their trips today to make way for the additional passengers using both systems for the first time in two months  today.

GO spokesperson Anne Marie Aikins says several new train routes are launching today to and from Union Station.

After a summer of making changes to the math curriculum, sex-education, class sizes and requirements for incoming teachers, Education Minister Stephen Lecce heralded the start of the new school year.

“Today is the first day of school. It's a tremendously exciting time for parents, educators, and students all across the province of Ontario,” Lecce said in a statement. “As Education Minister, one of my most important responsibilities is to make sure that the students of today get the skills and self-confidence they'll need to get good-paying jobs of the future.”