The National Highway Traffic Safety Administration (NHTSA) released the results of a new study in April that focused on the specific tire problems that contributed to collisions. The study used data collected via the National Motor Vehicle Crash Causation Survey for 2005 through 2007 to determine its findings.
The NMVCCS data used is a sample of 5,470 crashes. In 9% of them, one or more vehicles experienced tire-related problems before a crash. Out of the tire-related crashes, half (50%) involved a single vehicle. Out of crashes that did not involve tire-related factors, only 31% involved a single vehicle.
The study found a number of specific tire conditions that affect crashes, too. For example, when tires are underinflated by 25% or more, tire problems are three times as likely to be cited as critical events before a crash. Another finding is that of the SUVs that experienced tire problems before a crash, 45% of them rolled over. For other vehicle types than SUVs, though, fewer than 25% experienced tire problems before rolling over.
Tread depth was another factor. Of tires with tread depth in the range of 0 to 2/32 of an inch, 26% were in vehicles that experienced tire-related problems before a crash. Out of vehicles that had tire tread depths in the 3/32 to 4/32 of an inch range, though, only 8% involved in crashes experienced tire-related problems before the crash occurred.
The study also found that drivers who were less familiar with the vehicles they were driving experienced tire problems before a crash more significantly than “chance,” according to NHTSA.
Lastly, 11.2% of vehicles experienced tire-related problems when road conditions, such as a wet road, a road underwater, or just a slick surface, were present when compared with regular road conditions (only 3.9% of vehicles experienced tire-related problems before a crash).
Ford has recalled 151 of its 2018 F-650 and F-750 medium-duty trucks with hydraulic brake systems for an inadequate parking brake cable that could cause unintended movement.