Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles

Abstract

Systematic, well-designed research provides the most effective approach to the solution of many problems facing highway administrators and engineers. Often, highway problems are of local interest and can best be studied by highway departments individually or in cooperation with their state universities and others. However, the accelerating growth of highway transportation develops increasingly complex problems of wide interest to highway authorities. These problems are best studied through a coordinated program of cooperative research. In recognition of these needs, the highway administrators of the American Association of State Highway and Transportation Officials initiated in 1962 an objective national highway research program employing modern scientific techniques. This program is supported on a continuing basis by funds from participating member states of the Association and it receives the full cooperation and support of the Federal Highway Administration, United States Department of Transportation. The Transportation Research Board of the National Academies was requested by the Association to administer the research program because of the Board's recognized objectivity and understanding of modern research practices. The Board is uniquely suited for this purpose as it maintains an extensive committee structure from which authorities on any highway transportation subject may be drawn; it possesses avenues of communications and cooperation with federal, state and local governmental agencies, universities, and industry; its relationship to the National Research Council is an insurance of objectivity; it maintains a full-time research correlation staff of specialists in highway transportation matters to bring the findings of research directly to those who are in a position to use them. The program is developed on the basis of research needs identified by chief administrators of the highway and transportation departments and by committees of AASHTO. Each year, specific areas of research needs to be included in the program are proposed to the National Research Council and the Board by the American Association of State Highway and Transportation Officials. Research projects to fulfill these needs are defined by the Board, and qualified research agencies are selected from those that have submitted proposals. Administration and surveillance of research contracts are the responsibilities of the National Research Council and the Transportation Research Board. The needs for highway research are many, and the National Cooperative Highway Research Program can make significant contributions to the solution of highway transportation problems of mutual concern to many responsible groups. The program, however, is intended to complement rather than to substitute for or duplicate other highway research programs.

Stability of long combination vehicles

“…This model also allows the determination of the lateral (h 1 -the instantaneous lateral distance between the zero-reference frame and the centre of gravity -as shown in Figure13(a)) and vertical (h 2 -the instantaneous CG height -as shown in Figure 13(b)) CG location. Finally, if we consider the recommended maximum LLT ratio for the rear axle of 0.6 (Woodrooffe et al, 2010;Walker and Pearson, 1987), and also include the recommended bank angle and longitudinal slope of the road (AASHTO, 2001(AASHTO, , 2003, we can calculate the SRT factor for a trailer model on downhill and uphill corners. Table 4 shows a trailer model with different trailer/trailer angles (ψ).…”

“…Other researchers have described that the bank angle and the longitudinal slope of the road also influence the SRT factor calculation (Chang, 2001;AASHTO, 2003;Woodrooffe et al, 2010).…”

Issues and Options for Oversize/Overweight Permitting of Petroleum-Related Trucks in a Performance-Based Regulatory Context: The Manitoba Experience

“…This signing was the culmination of several years of technical research concerning the impacts of truck loads on pavements and bridges and the relationship between vehicle configuration (i.e., number of axles, axle spacing, trailer coupling devices) and dynamic stability and control. The main objectives of the MoU were to: (1) improve regulatory uniformity across jurisdictional boundaries; (2) enable economic opportunity by purposely increasing truck productivity; and (3) ensure that the newly regulated, more productive vehicles met specified safety-related dynamic performance criteria (Woodrooffe et al 2010;Regehr, Montufar, and Clayton 2009).…”

“…From a cubic perspective, tractor semitrailer and truck-trailer combinations are limited to 23 m (75 ft) and doubletrailer trucks are limited to 25 m (82 ft). Trailer lengths are limited to 16.2 m (53 ft) (Woodrooffe et al 2010;IBI Group and ADI Limited 1987).…”

“…In essence, the performance-based approach sought to regulate vehicles based on infrastructure impact and vehicle stability and control criteria such as braking, off-tracking, and roll stability. Based on a thorough engineering understanding of these impacts, truck size and weight "envelopes" providing a full vehicle specification of weight, axle configuration, and length limits were developed (Woodrooffe et al 2010). In this regard, the Canadian approach departs from the somewhat more prescriptive approach to regulating truck size and weight in the United States (save for perhaps the Federal Bridge Formula, which can be understood as a performance-based regulatory approach).…”