What Is the Speed Limit on Highways in Ontario?

Ontario's Highway Traffic Act sets default speed limits that apply whenever no sign is posted.

Ontario raised the limit to 110 km/h on select highway stretches as a pilot program, later made permanent on specific corridors. Affected roads are clearly posted. If you do not see a 110 km/h sign, assume 100 km/h on a controlled-access highway.

Reduced speed limits in construction zones must be obeyed whether or not workers are present. Fines for speeding in an active construction zone (workers on site) are doubled. Exceeding the posted limit by 50 km/h or more anywhere in Ontario is classified as stunt driving, triggering immediate roadside consequences.

The penalty for speeding increases with how far over the limit you are driving.

G1 and G2 drivers are held to the same posted speed limits as fully licensed drivers. However, any demerit accumulation hits stricter thresholds for novice drivers: 6 points triggers a warning, and 9 points means an automatic licence suspension. Staying at or slightly below the flow of traffic is safer and reduces risk of being pulled over.