Impact of Adopting Canadian Interprovincial and Canamex Limits on Vehicle Size and Weight on the Montana State Highway System

72835435833251https://doi.org/10.21949/15182171996Final, June 1994 to August 1996PDFTech ReportFHWA/MT-96/8113, Final Report, MSU G&C 2911878113Truck trafficTruck routesBridgesSize and weight regulationsVehicle sizeInterstate highwaysCanadian interprovincial limitsTruck effects (Bridges)Truck pavement damageBridges and other structuresEconomicsFinanceHighwaysLawMotor CarriersSocietyI10: Economics and AdministrationUnited StatesMontanaMontana State University--Bozeman. Civil Engineering Dept.Montana. Department of TransportationStephens, JerryScoles, JimPatterson, SteveSchillings, PaulMontana State University (Bozeman, Mont.). Department of Civil EngineeringMontana. Department of Transportation. Research, Development and Technology Transfer ProgramUnited States. Federal Highway AdministrationUS Transportation CollectionThe impact on the Montana state highway system of adopting Canadian lnterprovincial, Canamex, or Canamex Short limits on vehicle size and weight was determined. Canadian lnterprovincial vehicle configurations were developed based on an investigation of vehicle safety, economy, and damage to the highway system. Canamex and Canamex Short limits are hybrid size and weight systems that retain existing Montana axle weight limits coupled with Canadian gross vehicle weights. All scenarios allow vehicles to operate at higher gross weights than are presently allowed in Montana. The impact of these vehicles on the highway system was determined by a) developing traffic streams that included these vehicles, b) determining the engineering impact these traffic streams would have on existing bridges and pavements and on the future designs required to support these vehicles, and c) assigning a cost to these impacts based on the current cost of equivalent work. These analyses found that 16 to 20 percent of the bridges system-wide are deficient to carry Canadian lnterprovincial vehicles (above and beyond the bridges already deficient under HS20 loads). Incremental deficiencies under Canamex and Canamex Short vehicles are between 1 and 3 percent of the bridges system-wide. The results were found to be sensitive to the assumed level of bridge capacity and the specific segment of the system being considered (i.e., interstate, primary, etc.). Long term pavement demands under all scenarios considered increase by less than 5 percent compared to demands under the existing traffic stream. Based on these impacts, an increase in equivalent uniform annual cost (EUAC) for bridges and pavements of 12 to 42 million dollars was calculated for Canadian lnterprovincial limits. These costs represent a 11 to 36 percent increase in cost over that projected for the same activities under the existing traffic stream. An increase in EUAC of 4 to 7 million dollars was calculated for Canamex limits, which represents a 4 to 6 percent increase in cost over that projected for the same activities under the existing traffic stream. Similar but slightly higher costs were determined for the Canamex Short scenario relative to the Canamex scenario. These costs are for the interstate and primary systems. These costs represent an increased cost of 0.01 to 018, 0.02 to 0.08, and 0.02 to 0.15 dollars per mile driven on the interstate system by the new configurations for Canadian Interprovincial, Canamex, and Canamex Short limits. Similar costs per mile driven on the primary system were 1.3 to 10 times higher than these costs.90