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 2015, 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.
That being said, the extent of the restrictions, technical criteria, and time period can fluctuate and are dependent on the condition of the road and by region. For example, British Columbia’s South Coast Region will not have any load restrictions in place for 2015. More details by province can be found at the end of the article.
Spring Thaw Limits
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 load regulations, by axle weight, in Québec and Ontario:
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.
Preparation Tips: Spring Thaw Best Practices
- Collect regulatory information early: details about the limits for highways in each province are posted on the provincial transportation ministries’ websites.
- Pro-active and consistent communication: Operations Managers and Safety & Compliance departments should regularly communicate restriction guidelines to dispatchers, drivers, and operations teams.
- Provide training: 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.
- Operations and Safety & Compliance: 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.
More information about Spring Thaw regulations by province can be found here: