"Winter season weights for heavy haul and Period 4 season weights for service rigs remain in effect north of the thaw line."
| Field | Detail |
|---|---|
| Status | ACTIVE Spring/Period 1 weights in effect south of and including Township 35; Winter/Period 4 weights remain north of thaw line |
| Status Timestamp | 2026-03-11 at 20:13 UTC (source document last modified March 5, 2026) |
| Coverage | Alberta provincial highways only local and municipal roads not covered by this source |
| Effective Dates | Spring/Period 1 weights: effective 12:01 am Monday, March 9, 2026 south of and including Township 35. End date not specified. Winter/Period 4 weights remain in effect north of thaw line until further notice. |
| Weight Limits | Specific axle and gross weight values not published in this source. Contact Alberta Transportation or consult the applicable regulation for spring and winter season weight schedules. |
| Key Roads | Heavy haul roads and service rig roads on Alberta provincial highways. Thaw line boundary: Township 35 (as of March 9, 2026); prior boundary was Township 28 (as of March 5, 2026). |
| Exemptions | Not specified in this source |
| Penalties | Not specified |
| Contact | Alberta Transportation and Economic Corridors Frost Thaw Contour Map (PDF) |
| Primary Status Source URL | transportation.alberta.ca Frost Thaw Contour Map PDF |
Current Thaw Line Position
The Alberta frost thaw contour map depicts two thaw line positions for the current season. Use these boundaries to determine which weight season applies to your route:
- March 5, 2026: Thaw line at Township 28
- March 9, 2026: Thaw line advanced to Township 35
As of March 9, 2026, the operative boundary is Township 35. Roads south of and including Township 35 are under spring/Period 1 weight rules. Roads north of Township 35 remain under winter/Period 4 weight rules.
Weight Season by Zone
| Zone | Road Type | Active Weight Season | Effective Date |
|---|---|---|---|
| South of and including Township 35 | Heavy haul roads | Spring season weights | 12:01 am, March 9, 2026 |
| South of and including Township 35 | Service rig roads | Period 1 season weights | 12:01 am, March 9, 2026 |
| North of Township 35 (thaw line) | Heavy haul roads | Winter season weights | Ongoing no change date specified |
| North of Township 35 (thaw line) | Service rig roads | Period 4 season weights | Ongoing no change date specified |
Specific weight values (axle limits, gross limits) are not published in the frost thaw contour map source. Consult Alberta Transportation or the applicable weight schedule regulation for exact limits under each season designation.
Coverage Scope
- This source covers Alberta provincial highways only. The thaw boundary is defined by township lines as published on the provincial frost thaw contour map.
- Local and municipal roads are not covered by this provincial source. Contact the relevant municipality directly for local road restrictions.
- Road classifications affected: heavy haul roads and service rig roads.
Exemptions and Permits
No exemptions, permit categories, or commodity exceptions are specified in the frost thaw contour map source for the current restriction period. Verify exemption eligibility directly with Alberta Transportation and Economic Corridors before dispatch.
How to Use This Information for Dispatch
- Determine your route's position relative to Township 35 the current thaw line boundary as of March 9, 2026.
- If operating south of or at Township 35: apply spring season weights (heavy haul) or Period 1 season weights (service rigs).
- If operating north of Township 35: winter season weights (heavy haul) or Period 4 season weights (service rigs) remain in effect.
- The thaw line advances as temperatures rise. Check the frost thaw contour map PDF for updated boundary positions before each trip during spring thaw season.
- For real-time highway conditions, also consult 511.alberta.ca.
Source Attribution
| Field | Source | Retrieved |
|---|---|---|
| Restriction Status | AB Frost Thaw Contour Map PDF | 2026-03-11 20:13 UTC |
| Status Timestamp | AB Frost Thaw Contour Map PDF | 2026-03-11 20:13 UTC |
| Effective Dates | AB Frost Thaw Contour Map PDF | 2026-03-05 (doc modified) |
| Thaw Line / Regional Variations | AB Frost Thaw Contour Map PDF | 2026-03-05 (doc modified) |
| Road Classifications | AB Frost Thaw Contour Map PDF | 2026-03-05 (doc modified) |
| Weight Limits | Not published in source | |
| Exemptions | Not published in source | |
| Penalties | Not published in source |
