WASHINGTON — The National Highway Traffic Safety Administration (NHTSA) has more than doubled its estimate for highway deaths attributed to tire-related issues, but it has not provided an explanation as to why.
According to a page on NHTSA's site devoted to tires, the agency estimates there were 733 highway crash fatalities in 2016 "in which a contributing factor was a tire malfunction."
The figure of 733 fatalities in 2016 compares with the agency's statement on its "TireWise" informational site of "almost 200" a year.
The new estimate caught the attention of The Safety Institute, an affiliate of Rehoboth, Mass.-based Safety Research & Strategies Inc. (SRS). The company wrote NHTSA Deputy Administrator Heidi King Sept. 25 seeking an explanation for the discrepancy.
"While we are not aware of any actual work that NHTSA may have done based on methods that are scientifically defensible,…we are aware that NHTSA is now citing on its website two new statistics that are inconsistent with previous estimates the agency made in 2014," Sean Kane, president and founder of The Safety Institute and SRS, wrote on a blog post.
All of the sites cited by SRS estimate the number of tire-related crashes at 11,000 a year.
"Now that NHTSA is using an apparently defensible method to count tire-related crash fatalities, it would be appropriate for the agency to revise its TireWise safety information to reflect to reflect the correct information," Mr. Kane wrote.
"Most importantly, NHTSA must review past rule-making decisions for tire safety that were based on data and methods that are known to be unsuited to a statistical study of this topic," he wrote.
In a Sept. 26 blog item, SRS said the new statistics on the NHTSA website are much more in line than before with a study presented before the National Transportation Safety Board in December 2014 by Randy and Alice Whitfield of Quality Control Systems Corp.
That study, commissioned by The Safety Institute, challenged NHTSA's statistical analysis of tire crash data, the blog posting said.
In a telephone interview, Mr. Kane said the NTSB asked NHTSA at the time to review its analytical method for tire-related fatalities in light of the Whitfields' report.
"We want to know what they're going to do with this larger pool of tire fatality statistics that should help determine tire safety policy from now on," he said.
NHTSA has not yet answered the Sept. 25 letter, Mr. Kane said. "We don't know when they might answer, and we may get no response at all," he said. "We can never tell with NHTSA."