The imposition of road vehicle load and size standards essentially seeks to ensure the safety of road users and protect road infrastructures.
In the context of Québec trade, these standards make it possible to support the flow of goods by extraprovincial and international road transportation. The Ministère wishes to support the development of high-performance vehicles and harmonization with other administrations. This is why it participates in a Canadian Task Force, the main mandate of which is to maintain the Federal-Provincial-Territorial Memorandum of Understanding respecting an Agreement on Vehicle Weights and Dimensions. This Memorandum of Understanding came into force in 1988.
The Ministère also has other concerns related to sustainable development, such as the constraints regarding the environment and the application of these standards.
In Québec, since 1941, load and dimension standards are legislated. Section 621 of the
Highway Safety Code allows the Government to regulate the loads and sizes of vehicles circulating on Québec roads.
Vehicle Load and Size Limits Regulation combines various standards limiting, in particular, the size, loads per group of axles, and the total loaded mass of road vehicles circulating on public roads.
In thaw periods, specific measures apply to protect the road networks, which are about 40% more fragile. Three geographic areas allow application of load limit restrictions of about 10% to 20% in normal periods. Information on these restrictions is available in the section
Thaw – Load Restriction Period.
For the past several years, the Ministère has sought to harmonize the Québec standards with those of other North American administrations. However, despite these efforts, differences may still persist. Even if a vehicle is in compliance with the Québec regulations, it is important to check the rules applicable in the other administrations before driving there.
The Vehicle Load and Size Limits Regulation applies to all heavy and light road vehicles. It does not concern road vehicles designed to fight fires. The operator, the owner, the shipper and the driver must ensure compliance with this Regulation's standards.
Good load distribution improves the vehicle's dynamic behaviour (manoeuvrability, road handling, etc.), thus reducing accident risks.
Circulation of an overloaded vehicle, regardless of type, speeds up degradation of the road network and thereby increases the rehabilitation costs.
For example, it is estimated that a 2000 kg axle overload on the tandem of a tractor hitched to a semi-trailer equipped with a triple axle increases degradation of the road network by 11%, even if the total loaded mass limit of 49,500 kg of the combination of vehicles is respected.
They must ensure they use a vehicle that meets the manufacturing standards in force. Moreover, its use must be suited to the usage for which it is intended.
Anyone who contributes to putting one or more road vehicles into operation on public roads assumes a share of the responsibility.
The obligations specific to each party are as follows:
Since October 1, 2007, a section of the Highway Safety Code allows a more equitable sharing of responsibilities among the stakeholders in case of interception of a vehicle with an overloaded total mass. Section 517.2 applies to heavy vehicles with or without a special permit, when the load is considered to be a full load.
Under this section, the sharing of responsibilities is based on the comparison between the loaded mass when the vehicle is weighed and the loaded mass reported by the shipper. Three ways of sharing responsibilities between the operator and the shipper are prescribed by section 517.2. It also determines the documents required aboard the vehicle.
The latest amendments to the Vehicle Load and Size Limits Regulation have been in force since February 14, 2013.
The load limits authorized in Québec are comparable to those of the neighbouring authorities. Québec has achieved major efforts in the past few years to harmonize its load limits with those in force for its trading partners.
The road structures are designed to meet a certain stress level. In other words, the roadways must be able to support a foreseeable quantity of trips by vehicles, including trucks, during a given time, before the road necessitates total or partial reconstruction. Thus, the roadway life cycle depends on whether this number of trips has been attained or not.
Consequently, a stress that differs from the initially projected scenarios will affect the evolution of the road network. We know Québec roadways have not all been designed to handle the traffic we know today, and this influences their behaviour. This is why the Ministère has adopted pavement monitoring and management tools, and an intervention strategy that allows preservation of the works.
A reduction of load limits in normal and thaw periods certainly would have the effect of reducing the damage caused to the road network. The network maintenance cost thus could be reduced significantly. However, the economic costs of such a reduction of load limits for the industry would hurt Québec's economy.
Moreover, a reduction of the load limits would have the effect of increasing the number of vehicles, which is necessarily beneficial for the road network or the environment. An increase in the number of heavy vehicles could also have an impact on road safety.
© Gouvernement du Québec, 2021