Safety performance of longer combination vehicles relative to other articulated trucks

Abstract

This article helps improve the understanding about the safety performance of longer combination vehicles (LCVs) relative to other articulated trucks operating on rural highways, using evidence from the Canadian portion of the CANAMEX trade corridor. The analysis reveals that from a collision rate perspective, LCVs as a group have better safety performance than other articulated trucks. Turnpike doubles have the lowest collision rate of all articulated truck types (16 collisions per 100 million vehicle-kilometres of travel or VKT), followed by Rocky Mountain doubles (32 collisions per 100 million VKT). The collision rate for triple trailer combinations (62 collisions per 100 million VKT) is higher than the collision rates for tractor semitrailers (42 collisions per 100 million VKT) and legal-length tractor double trailers (44 collisions per 100 million VKT). These results are an important input for civil engineering and transport policy decisions concerning longer combination vehicle operations.

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

“…Studies have shown 87, (88), (89) that the safety performance of LCVs operating under special permit in Canada has been very encouraging when compared with tractor semitrailers. Turnpike doubles have the lowest crash rate of all LCVs, between 2.5 and 5 times less than standard tractor semitrailers (87), (88), (89), (90). LCVs also have significant environmental benefits due to the improved efficiency of the vehicles.…”

Regulations governing the operation of longer combination vehicles in Canada

“…Based on a survey of LCV carriers, Nix (1995) estimates that total annual LCV travel in Alberta, Saskatchewan, Manitoba, and Québec (the four provinces that permitted LCVs at the time) amounted to 71 million kilometres. In Alberta, Regehr et al (2009b) As the LCV network expands and LCV operations grow, the need for inter-jurisdictional regulatory harmonization has become apparent. The recent (2012) memorandum of understanding (MoU) signed by the four western provinces (i.e., British Columbia, Alberta, Saskatchewan, and Manitoba) demonstrates a desire to create a seamless operating environment for inter-jurisdictional LCV activity.…”

“…That is, while it enabled intra-jurisdictional movements (e.g., between Calgary and Edmonton, Alberta; between Regina and Saskatoon, Saskatchewan; between Winnipeg and Brandon, Manitoba), gaps in the network precluded significant levels of inter-jurisdictional LCV movement. As these gaps were closed, however, available evidence shows a corresponding increase in the levels of LCV activity in the region (Regehr 2009;Regehr, Montufar, and Clayton 2009a;Regehr et al 2009b;Di Cristoforo et al 2012).…”

Lessons learned about the impacts of size and weight regulations on the articulated truck fleet in the Canadian prairie region

“…These characteristics are fundamental inputs to nearly all aspects of highway engineering. Principal examples are: the analysis of traffic operations impacts of articulated trucks and the related design of road geometry (Harkey et al 1996;Elefteriadou et al 1997); the development and use of load spectra for mechanisticempirical pavement design (Hajek et al 2002;AASHTO 2008), and the design and evaluation of bridge structures (Ghosn and Moses 2000;National Cooperative Highway Research Program 2003); the determination of the safety performance of articulated trucks in terms of collision rates (Regehr et al 2009); and the analysis of energy, fuel, and emissions impacts of different types of articulated trucks (ATRI 2008).…”