Alberta Frost Laws, Seasonal Load Weight and Speed Restrictions – 2026

"Last Modified: April 2, 2026"

Upcoming Restriction: What Changes on April 6, 2026

Effective 12:01 am Monday, April 6, 2026, spring season weights for heavy haul and Period 1 season weights for service rigs will come into effect on roads province-wide across Alberta provincial highways. This is a province-wide simultaneous activation no regional phasing is indicated for the April 6 effective date. Prior to April 6, existing weight rules remain in effect.

Thaw Line Progression (Contour Map Record)

The frost thaw contour map documents the northward advance of the thaw front across Alberta through the 2026 spring season. The following dated boundary positions are recorded on the current map:

• March 5, 2026: Thaw line at Township 28
• March 9, 2026: Thaw line advanced to Township 35
• March 19, 2026: Thaw line advanced to Township 58

These contour lines illustrate the spatial progression of the thaw front. The April 6, 2026 province-wide activation supersedes the earlier zone-by-zone thaw line approach documented in previous map revisions.

Weight Season Summary

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 province-wide activation on April 6, 2026 applies to the full provincial highway network.
• 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 routes and service rig routes (Period 1).

Exemptions and Permits

No exemptions, permit categories, or commodity exceptions are specified in the frost thaw contour map source for this restriction period. Verify exemption eligibility directly with Alberta Transportation before dispatch.

Dispatch Checklist

• Spring/Period 1 weights are not yet active as of the April 2, 2026 document date. They activate at 12:01 am Monday, April 6, 2026.
• On and after April 6, apply spring season weights (heavy haul) or Period 1 season weights (service rigs) for all trips on Alberta provincial highways, province-wide.
• Specific per-axle and gross weight limits are not stated in the contour map source obtain the applicable weight schedule from Alberta Transportation before dispatch.
• Check the frost thaw contour map PDF before each trip for any updated effective dates or boundary changes.
• For real-time highway conditions, also consult 511.alberta.ca.