Ministry of Transportation
MTO
Ontario • Canada
The Ontario Ministry of Transportation (MTO) manages over 17,000 kilometers of provincial highways including the 400-series expressways that are the backbone of Canada's most economically productive province. Key freight corridors include Highway 401 (the world's busiest highway, handling over 500,000 vehicles/day near Toronto), Highway 400, Highway 403, Highway 417 (Ottawa), and the QEW. Ontario accounts for roughly half of all Canadian manufacturing output, and MTO's highway network supports massive automotive, electronics, and food processing freight flows. The ministry administers the Ontario commercial vehicle permit system, operates the COMPASS traffic management system, and provides 511Ontario for real-time road conditions, especially at the critical US-Canada border crossings at Windsor-Detroit and Niagara.
| Official Website | https://www.ontario.ca/page/ministry-transportation |
|---|---|
| Data API | https://511on.ca/developers/doc |
| Founded | 1916 |
| Headquarters | Barrie |
Available Data
Social Media
- @511Ontario — 511Ontario
Ontario Trucking Regulations
Size & weight limits, OS/OW permits, and seasonal restrictions for commercial vehicles
Weight Limits
| Category | Limit |
|---|---|
| Max Gross Vehicle Weight | 63500 kg |
| Single Axle | 9000 kg |
| Tandem Axle | 18000 kg |
Dimensional Limits
| Category | Limit |
|---|---|
| Max Height | 4.15 m |
| Max Width | 2.6 m |
| Max Length (Single Unit) | 12.5 m |
| Max Length (Combination) | 25 m |
OS/OW Permits
Seasonal Restrictions Mar, Apr, May
Annual spring weight restrictions (typically late March to mid-May) reduce maximum axle weights by 25–35% on provincial highways during frost break-up. The MTO designates restricted roads each spring under O. Reg. 413/05. Northern Ontario secondary highways tend to be restricted longer than southern routes.
14.3¢/L
Member
Special Exemptions
Notable Rules
Ontario permits B-train combinations up to 27.5 m on designated MTO B-train routes in northern Ontario. Height limit of 4.15 m is lower than western provinces — older bridges, especially on county/municipal roads, may have even lower postings. The 400-series highway network in the Golden Horseshoe (Toronto–Hamilton–Oshawa) carries the highest commercial freight density in Canada. Windsor–Detroit and Sarnia–Port Huron are among North America's busiest border crossings.