Let’s start with Rae Tyson, director of media relations, National Highway Traffic Safety Administration (NHTSA). Rae, tell us about the study.

Rae Tyson: “A lot of information has been released in the debate of who is responsible for tire debris, but we found it was difficult to collect the background data from these studies. While others were interested in the origins of the rubber on the road, the National Highway Traffic Safety Administration’s (NHTSA) primary objective was to learn if tire debris poses a safety concern to the motoring public.”

How was the data collected?

We hired the University of Michigan Transportation Research Institute (UMTRI), which has tremendous knowledge in this area, to conduct the study.

Five diverse areas in the country were identified to collect samples, and included a range of environments, such as flat landscapes where higher speeds could be attained, to rolling hills where speed is controlled with frequent heavy braking; a variety of interstate and highway road surfaces; and a range of ambient temperatures. The study was conducted in the summer of 2007, and median temperatures were as low as 75 degrees in Gary, Indiana and as high as 97 degrees in Tucson, Arizona.

Transportation departments in these five states gathered 1,196 tire fragments, while five truckstops, located in the same five areas, collected 300 discarded casings.

The casings and tire fragments were analyzed by tire forensic experts Smithers Scientific Services in Akron, Ohio.

The first task for Smithers was to determine whether the casing and tire debris were from a retreaded or new tire.  Of the casings, approximately 43 percent were retreaded and 57 percent were original.

Was that surprising?

No, not at all. The percentage of original tread and retreaded tires varies from year to year, depending on availability of good-paying freight, number of new tractors and trailers, and concentration of vocational fleets in the area, such as waste and construction.

Of the tire debris collected, Smithers concluded 68 percent was from retreaded tires, 18 percent was from new tires and 14 percent couldn’t be identified.

A majority are retreaded tires.

True, however the 52 percent of the tire debris was identified as being from the trailer axle position. Considering a majority of trailers run on retreaded tires, this outcome was expected.

We interviewed fleet managers for the study, and they said trailer tires are especially vulnerable to damage from road hazards. First of all, in ‘drop-and-hook’ operations, many trailers are not owned by the fleets that pull them, so few take the time to check inflation pressures or air up the tires. These underinflated tires are more susceptible to punctures, cuts and scrapes than those properly inflated.

Fleet managers also reported while drivers do a good job of steering away from a road hazard, the trailer tires are likely to track right over it. And last, curbing damage takes a toll on trailer tires.

What is the conclusion of the study? Are retreads the culprit for rubber on the road?

Not at all. Road hazards are the common cause of tire failure, affecting both retreaded and new tires almost equally.

Analysis of all tire casings found maintenance and operational issues accounted for 33 percent of the failures while over-deflection accounted for 16 percent.

Of the tire fragments, excessive heat was evident
in 30 percent.

And what about safety?

As I said earlier, the reason for funding this study was to learn if tire debris was causing vehicle crashes, either related to truck tire failure or debris in the roadway. The study found they account for less than one percent of accidents.

What do you think the public should take from this study?

“It certainly helps them understand where the debris is coming from, and people can make wise decisions based on good, sound, scientific evidence.”

Now let’s talk to Kyle Jensen, manager of industry and government relations at Bridgestone Bandag Tire Solutions.

Kyle, the misconception is that retreads are the cause of road debris, yet most of the samples were attributed to retreads.

What is your reaction?

Kyle Jensen: “Yes, retreaded tires are overrepresented, however, if you look at the reasons why tires fail, it’s not because the tires were retreaded or the result of a deficiency in the process.”

What do you mean?

“Let’s take a look at the probability of retreaded tires being affected from a mathematical standpoint.

“Fleets operate 15 million retreaded tires in the U.S.

“Up front, few steer axles are retreaded. On the drive axles, about 50 percent are retreaded tires, while around 70 percent of trailer axles are on retreaded tires.

“Of course these numbers can go either way depending on the size of the fleet, age of the equipment and vocation.

“But on a typical long haul tractor, there’s a better chance the tires are new. And on a typical long haul trailer, there’s a better chance the tires are retreaded. And we know most of the ‘gators’ can be traced back to the trailer axles.”

Do you believe this government study can sway public perception?

“Actually NHTSA’s study isn’t the first; Arizona and Virginia published their own findings that came to the same conclusion.

“And, you may have seen a science-based television show try to bust the myth that rubber on the road is created by retreaded tires.

“Even with sound, scientific evidence, it’s not unusual to run across a person who still firmly believes that all tire debris is from retreads.” 

So what can we do?

“Talk about it. Bust the myth at every opportunity. Like many urban legends, the story will simply die and the truth will be overwhelmingly accepted.

“For example, a generation of children were drilled to slightly open a window to equalize pressure during a tornado. Luckily, people understand there’s solid, scientific evidence cautioning them to stay away
from windows.

“Between 1972 and 1978, the Chevrolet Nova was sold in Mexico and Venezuela. Over 30 years later, people are finally realizing there’s no truth behind the legendary ‘no go’ Spanish translation myth, thanks in part to linguistic evidence – and the Internet.

“Fleets both large and small need to talk about the positives in retreading so we can bust this myth once and for all. In fact, everybody involved in the trucking industry needs to talk about it.”

Where should we start?

“Begin with technology and recycling. Tell people that fleets are more environmentally progressive than many consumers, and using retreaded tires is an outstanding example.

“We also need to change the amount of tire debris found on our roads. That means doing a better job inspecting tires and maintaining inflation pressures.

“I know I’m preaching to the choir about this but underinflation is the biggest reason for debris and casing failure on the road. Most road hazards could be a smaller threat and cause less damage if tires are properly inflated.

“Overdeflection is the second cause of tire debris and it’s a result of not having enough air in the tires. When overdeflected tires are driven too long and too far, the excessive heat generated causes the tires to break apart, littering the road with rubber debris. And that’s what people are seeing. So they contact their congress people and holler for retreads to be outlawed.”

And we’re back to where we were.

“Exactly. We have to be the catalyst for busting the myth. And we have good, solid, independent scientific evidence to back us up."