On-Site Magazine

Improving seasonal road restrictions

December 8, 2014   By Provided by the Canadian Ready-Mixed Concrete Association

As we head into another frosty Canadian winter, many con­tractors are already looking ahead to the spring thaw. And for good reason. The construction industry is challenged by seasonal load restrictions (SLRs) that are imposed on road infrastructure by municipalities to limit damage as the soil returns to normal conditions.

These restrictions have been in place for years and they limit the amount of axle loading a transportation vehicle can transfer to an affected roadway. The restrictions are imposed on roads deemed to have a subgrade that is susceptible to frost and where there is a history of significant movement of the subgrade that degrades the road.

The concerns with the restrictions and the reasons for them vary from municipality to municipality. Some cities put the signs up as part of an annual maintenance schedule, even though the winter weather has not dictated significant frost penetration and therefore does not distress the road. Most municipalities will allow for short-term permits at an additional cost. This permit process is not always clear on how to obtain or what rationale can be used for getting a permit, except to pay an additional fee.

Another issue that arises is whose responsibility is it to obtain the permit. The general contractor is obligated under his contractual arrangement to complete the work in the scheduled time frame, so he should plan for this based on the location and schedule. In most cases the general contractor will rely on his subcontractors to obtain the necessary permits.

Another issue that creates an uneven playing field is enforce­ment varies from municipality to municipality. Some cities are large enough to have their own enforcement, while others rely on transportation ministries or provincial police force.

SLRs plague the ready mixed concrete industry because they’re viewed as heavy equipment by the nature of their trucks and are easily identifiable as they proceed down a restricted road. Other vehicles that supply the same job site often avoid permits, as they’re not questioned in the same way. This creates an uneven playing field and puts the ready-mix industry in an illegal position should they follow the lead of other industries.

Our own industry has for years interpreted the SLR as half a load, which on average for a ready mix truck implies four instead of eight metres. In Ontario, based on the loading of 5,000 kilograms per axle, the standard truck can barely carry one metre of concrete. In some provinces they are a percentage of the allowable axle load. In the case of a ready mix truck without an exemption permit, at one metre per load a normal 32-metre pour would require 32 trips instead of the usual four based on an eight-metre truck. On the surface this complies with the regulations, but does it make sense to have eight times as many trips on the road that you are trying to minimize damage to?

Uneven enforcement leaves the ready-mix industry at a disad­vantage and creates higher loading on the roadways in question. A corollary impact is the increased affect on the environment by more fuel usage and CO2 emissions.

To address these concerns the Ready Mixed Concrete Association of Ontario hired a consultant to look at the loading characteristics of the industry with respect to new equipment and the actual impact on the roads during the restricted seasons. The evaluation concludes that going to a 6,500 kilogram per axle standard creates less fatigue cracking than the current 5,000 kilogram per axle. This allowance would increase the actual limitation on a standard ready mix truck to four metres per load instead of eight. The report also explains the savings related to the jobsite in terms of travel and additional labour imposed by traveling around restricted roadways.

The last key element is the estimate of environmental impacts; including the reduction of CO2 and greenhouse gas emissions should a higher axle allowance be used. The report has been struc­tured in the form of a toolkit that members in Ontario can use to contact their local municipality and present their case for a relaxation of the SLR based on facts. The toolkit explains who to contact and how the process of presenting the information should be handled.

It is hoped that through this process, successful examples of permits of the new allowance can be documented and provide a series of case studies for the industry to further its technical argu­ment across Ontario and the rest of Canada.


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