2006-01-24_PWETC_AgendaPacket - Laserfiche WebLink

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Longer combination vehicles are incompatible with Minnesota's roads . Heavier, longer trucks are so big and slow they will have trouble merging or changing lanes. Their sheer size will make them particularly dangerous on smaller state and county roads. . LCVS have problems maintaining speed on upgrades. A 15 mile-per-hour speed differential increases accident risk nine times. (An Assessment of Changes in Truck Dimensions on Highway Geometric Design Principles and Practices, The University ci Texas Center for Transportation Research, 1981) . Because they are so long and heavy, LCVs create a larger crash "footprint," meaning that when they are involved in an accident, more cars will be invoived, too. . Because they have more articulation points, LCVs also have a greater risk of trailer separation. . LCVs do not need to crash to cause accidents. They also cause "systems" safety effects as other highway users speed up, slow down, or change lanes to avoid them. Heavier single-trailer trucks are also unsafe . Heavier truck weights mean a greater risk of fatalities, according to the University of Michigan Transportation Research Institute (UMTRI). (Comprehensive Truck Size and Weight Study, USDOT, Phase 1, Working Papers 1 and 2, 1995, p. 37) . The extra weight in a truck is typically stacked vertically, raising the center of gravity and increasing risk of rollovers. . Adding an extra axle to heavier trucks to mitigate pavement damage makes them harder to steer, increases the risk of skidding, and makes emergency maneuvers more difficult. It also increases brake maintenance problems, which can lead to longer stopping distances. The Commercial Vehicle Safety Alliance found during its Roadcheck 2005 that 30% of the trucks inspected had brakes far enough out of adjustment for the trucks to be taken out of service. Bigger Trucks Damage Bridges and Highways Damage to bridges . Heavier trucks erode the design margin of error that ensures against bridge failure, increasing the number of bridges that must be replaced, strengthened, or posted. . At the end of 2004, there were 1,633 structurally deficient or functionally obsolete bridges in Minnesota. (Nationa/Bridge Inventory, FHWA, December 2004) . According to MNDOT, a 20% increase in weight almost doubles the fatigue damage to bridge decks, beams, and trusses. This would shorten the lifespan of bridges and lead to the posting of 10 additional trunk highway bridges and 500 local bridges. (OvelViewof Bridge Design Loadings, Load Postings, and impact of Heavier Truck Weights, Presentation by MNDOT to MN Senate Transportation Committee. January 2005.) . Nationwide, the USDOT calculated that six-axle. 97,000 pound tractor-trailers - the NAFTA truck being considered by MNDOT - would contribute to additional bridge costs of $329 billion ($65 billion in capital and $264 in user delay costs). Damage to highways . According to MN DOT, even with extra axles, the heavier truck configurations MNDOT has proposed have the potential to cause unspecified localized increases in pavement damage on all of the roads where these trucks would be allowed to operate. Damage to quaiity of life . Bigger trucks do not mean fewer trucks. Allowing heavier and longer trucks on state roads will divert traffic -1