Monday, October 21, 2018

Tire failures due to exceeding

Max Speed Rating

The National Highway Traffic Safety Administration (NHTSA) Office of Defects Investigation (ODI) recently closed an investigation into 2014 Michelin XZA 295/60/R22.5 tires.  The investigation was in response to numerous blowouts reported by auto hauler companies.  However the ODI concluded that the failures were not the result of design or material specification change and that the “more likely explanation of failures is the increase in maximum speed limits in several states”.  Therefore, it would appear, that the failures were due to the negligence of the operators driving over the maximum speed rating for the tires.  Currently, according to NHTSA, no truck tire is rated in excess of 81 mph or a speed rating of “M” and the vast majority are rated at 75 mph or a speed rating of “L”.  Nevertheless 16 states have maximum truck speeds equal to or greater than 75 mph, four of which allow 80 mph or more. NHTSA discovered during a special level 4 inspection survey that 55% of the trucks inspected have an overloaded tire based on the actual load and inflation pressure.  Further 60% of the drivers did not know the proper inflation pressure for the vehicle they were driving.

Peterbuilt recalls due to risk of

tire failure

Peterbuilt recently recalled over 1,600 semitrailers that mostly haul automobiles due to the fact they have speeds programmed to travel as much as 10 mph over the maximum speed rating of their tires.  The vehicles were equipped with tire with a maximum rating of 65 mph while some may have vehicle speeds programmed at more than 75 mph. “In vehicles described above that are used in the auto hauler application, a premature tire failure may occur on the front or steer axle as a result of certain operating conditions (i. e. higher speeds and road tempeature),” according to Peterbuilt in NHTSA documents.

Speed limiters for large

commercial vehicles proposed

by U. S. DOT

The U. S. DOT is proposing to require all newly manufactured U. S. trucks, buses and multipurpose passenger vehicles with a gross weight rating of 26,000 pounds to be equipped with speed limiting devices in the 60 to 68 mph range.  Motor carriers operating commercial vehicles in interstate commerce would be responsible for maintaining the devices at or below the designated speed for the service life of the vehicle.

Blog

Accident Investigation &

Reconstruction News

The following are summaries of recent safety and transportation articles which we found interesting and are posted for informational and educational purposes only.