As winter turns to spring in Canada, the layers of materials that compose roads are significantly weakened by an excessive amount of water in the road base, as a result of the annual spring thaw. Studies conducted by the provincial transportation ministries and Canadian Highway Research programs have shown that pavement reactions to a load are 50% to 70% greater in the spring than any other season. For trucks travelling across highways every day, this means that the same axle can cause between five to eight times more damage to the road in the spring than it would at any other time of the year.
In order to reduce the amount of damage done to roads, every Canadian province issues an annual “Spring Thaw” policy. Enforced by the province, the policy restricts loads carried across at-risk highways for a fixed period. For example, in 2017, Ontario’s spring thaw restrictions will run from March to June in some areas of the province, whereas highways in New Brunswick will be regulated from March to May.
The extent of the restrictions, technical criteria, and time period can fluctuate and are dependent on the condition of the road and by region.
2017 Spring Thaw Periods By Province
|Province||Zones/Counties||Spring Thaw Dates|
|British Columbia1||–||Spring thaw dates differ by region|
|Alberta2||–||March 20 until further notice|
|Saskatchewan3||–||March 20 until further notice|
|Manitoba4||Zone 1||March 20 – May 31|
|Zone 2||March 27 – May 31|
|Zone 3||March 31 – June 10|
|Ontario5||Schedule 1 Highways||March 1 – April 30|
|Schedule 2 Highways||March 1 – May 31|
|Schedule 3 Highways||March 1 – June 30|
|Quebec6||Zone 1||Feb 27 – April 28|
|Zone 2||March 27 – May 26|
|Zone 3||March 27 – May 26|
|New Brunswick7||–||March 5 – May 14|
|Northern New Brunswick||March 12 – May 21|
|Nova Scotia8||Yarmouth, Shelburne, Lunenburg, Digby, Annapolis, Kings Counties||March 6 – May 8|
|Halifax, Hants Counties||March 6 – May 8|
|Colchester, Cumberland, Pictou Counties||March 13 – May 15|
|Antigonish, Guysborough, Richmond, Inverness, Victoria, Cape Breton Counties||March 13 – May 15|
2017 Spring Thaw Weight Restrictions
Road reductions impose restrictions on vehicle load weight and size. This will usually include limitations on vehicle length, axle load and spread, and the total loaded mass of vehicles and vehicle combinations.
On average, 50 – 90% reductions are imposed on carriers during spring thaw; the exact limits are determined based on highway class, annual frost, and road tolerance testing. Although primary highway networks are excluded from regulations, it is not uncommon for highways to be temporarily re-classified during this period and subjected to seasonal load limits.
The following table shows a sampling of the extent of spring weight restrictions for Québec and Ontario, by axle weight.
|Province||Load Restriction||Compare To Basic Regulation|
|Québec||Reduced tandem axle weight of 15,500 kg||Down from 18,800 kg|
|Québec||Reduced tridem axle weight for 2.4m –
< 3m axle spread of 18,000 kg
|Down from 21,000 kg|
|Québec||Reduced tridem axle weight for 3m –
< 3.6m axle spread of 21,000 kg
|Down from 24,000 kg|
|Québec||Reduced tridem axle weight for 3.6m – 3.7m axle spread of 22,000 kg||Down from 26,000 kg|
|Ontario||5 tonnes (5,000kg) per axle where posted||Down from normal Highway Traffic Act standards|
More detailed information about spring road and weight regulations by province can be found here:
It is important to note that spring weights may change without any notice, based on weather conditions.
Load Inspection and Penalties During Spring Thaw
Under the Canadian safety and compliance policy, vehicles that exceed the load limits upon inspection will not be allowed to proceed until they meet the weight restrictions. This policy immediately prevents overloaded trucks from further damaging the road. Truck drivers must either spread the load more evenly between axles or unload any excess weight before proceeding to drive. It’s important to recognize that not only do overloaded trucks cause destruction on the roads, but excess weight can also affect the vehicle’s performance and on-road safety.
Penalties for not meeting spring thaw regulations will cost the carrier money, time, and demerits. The monetary penalties start at $350, the vehicle is held at roadside until overweight is removed, and the carrier will also receive points against their NSC (National Safety Code) profile.
Spring Thaw Preparation Tips & Best Practices
Collect Regulatory Information Early
Engage In Pro-active And Consistent Communication
Provide Appropriate Training To Drivers
Put Operations and Safety And Compliance Measures In Place
Details about the limits for highways in each province are posted on the provincial transportation ministries’ website.
Operations Managers and Safety & Compliance departments should regularly communicate restriction guidelines to dispatchers, drivers, and operations teams.
Ensuring that drivers are properly trained and aware of load restrictions is important. If drivers are not educated on how to prepare a load, or a vehicle, to meet weight restrictions, it will cost the carrier upon inspection.
Companies should put training and/or instructional programs in place to ensure compliance with Spring Thaw regulations. Failure to do so can result in steep penalties, downtime, vehicle performance, and ultimately, road safety.