Evolution of Bridge Live Load Models and Truck Weight Limits:The Case of Manitoba, Canada

Truck size and weight regulations have been a key instrument used to improve trucking productivity, safety, and operational performance in Canada. In response to these changes, bridge design codes undergo modifications to envelop the potential range of trucks in operation. A five-decade timeline is presented: (1) to document how bridge codes and their live load models have evolved, with a focus on the Manitoba-specific HSS-25 truck, and (2) to discuss how responsive bridge design codes have historically been to changes in truck size and weight regulations. While at times bridge codes are released in conjunction with expected regulation changes, there is often delay in the issuance of revised bridge design and evaluation codes. Assessments of the current truck fleet, which now includes long combination vehicles (LCVs), may be a consideration for future bridge design live load models.

Retrospective Longitudinal Study of the Impact of Truck Weight Regulatory Changes on Operating Gross Vehicle Weights

Three primary policy changes on truck size and weight occurred in Canada over the past five decades: the 1974 Western Canadian Highway Strengthening Program, the 1988 Roads and Transportation Association of Canada Memorandum of Understanding on Heavy Vehicle Weights and Dimensions, and ongoing special permitting of longer combination vehicles. These regulatory changes influenced the gross vehicle weight (GVW) of the predominant truck configurations operating on principal Canadian highways. Using a unique time-series of truck weight data, this retrospective longitudinal study contributes insights about the magnitude and timing of the impacts of truck weight regulatory changes on operating GVWs that address current knowledge gaps and persistent uncertainties in models used to predict and evaluate truck weight regulatory changes. The analysis reveals that carriers hauling heavy (i.e., weigh-out) commodities adapt immediately to increases in GVW limits if there is no need to purchase new vehicles. When a regulatory change coincides with the introduction of a new, more productive vehicle configuration, the uptake of the new vehicle lags behind the regulatory change by a few years. Finally, configurations exhibit different GVW distributions and responses to increased GVW limits depending on whether the configurations are well suited for hauling weigh-out or cube-out commodities. This differential response demonstrates how regulations facilitate fleet diversity within the trucking industry’s approach to the road freight transport task.

Regulations governing the operation of longer combination vehicles in Canada

The permits governing longer combination vehicle (LCV) activity in Canada aim to leverage LCV productivity advantages relative to other truck configurations while subjecting LCV operations to stringent regulatory controls. As of 2016, nine of the 13 provinces and territories permit LCV operations on a 17 000 km highway network. This article synthesizes LCV regulations in these jurisdictions within five categories: (i) carrier permit requirements, (ii) truck size and weight limits, (iii) equipment requirements, (iv) operating conditions, and (v) driver qualifications. While jurisdiction-specific differences remain, the synthesis reveals regulatory uniformity at the regional level. The article identifies how these regulations influence highway design, operations, and management decisions concerning the accommodation of LCV performance characteristics, the spatial and temporal control of LCV operations, the eligibility of drivers and carriers to operate LCVs, and opportunities for regulatory harmonization. As LCV activity increases, the need to formally consider the characteristics of LCVs within these decisions becomes more apparent.

Improving the Sustainability of Road Freight Transport by Relaxing Truck Size and Weight Restrictions

Increasing legal limits on the size and weight of trucks allows companies to achieve a higher degree of load consolidation. This reduces the total number of vehicle-kilometres required to distribute a given quantity of goods, saving money and reducing environmental impacts. Proposals to legalise longer and heavier vehicles, (LHVs) have, nevertheless, generated intense debate, particularly in Europe where they are strongly resisted by railway and environmental organisations. This chapter reviews recent studies on this subject, presents an analytical framework and focuses on three critical issues: the extent to which loads can be consolidated in LHVs, their effect on the freight modal split and the possibility that the resulting reduction in road freight costs will stimulate additional traffic growth. Most of the recent studies support the development of LHVs, particularly those based on actual experience of their use in countries such as Australia, Sweden and the United States.

Improving the Sustainability of Road Freight Transport by Relaxing Truck Size and Weight Restrictions

Increasing legal limits on the size and weight of trucks allows companies to achieve a higher degree of load consolidation. This reduces the total number of vehicle-kilometres required to distribute a given quantity of goods, saving money and reducing environmental impacts. Proposals to legalise longer and heavier vehicles, (LHVs) have, nevertheless, generated intense debate, particularly in Europe where they are strongly resisted by railway and environmental organisations. This chapter reviews recent studies on this subject, presents an analytical framework and focuses on three critical issues: the extent to which loads can be consolidated in LHVs, their effect on the freight modal split and the possibility that the resulting reduction in road freight costs will stimulate additional traffic growth. Most of the recent studies support the development of LHVs, particularly those based on actual experience of their use in countries such as Australia, Sweden and the United States.