Tires: Cause of Auto Accident Resulting in Serious Injury to Child, goodyear auto service center, center divider

Question
Tires were rotated and tread noted by a Goodyear auto service center on Sept 12.  Tread for all four tires were at 6/32.  Auto accident occurred 3 mo later (12/22).  Witness stated: "I noticed one of the right side tires bend to 1 side and suddenly explode.  At that point the driver lost control due to the tire explosion and swerved to the center divider and crash." Officer observed that "tires were Radial SXT All Terrains. DOT number on the tires were XFA 0307 and the tire size was 75/16's.  All four tires showed signs of dry rot that was located along the wall of the tire and the tread.  The dry rot was located along the area where the tread separated from the right rear tire."  The car was a 2001 Ford Explorer.  Im a really good lawyer, but no little about tires or dry rot. Would you expect the dry rot to be visible in the September inspection?  Is this something that the owner of the car would be expected to know or see, such that the car owner is possibly at fault rather than the tire manufacturer, or the facility that did the service three months before the accident. If you can even say?  Thank you in advance for any assistance you can provide.

Answer
Jacqueline,

First, I note that you are in Hawaii.  I'm assuming the accident took place in Hawaii.  I know there are things that are unique to Hawaii that are different than the rest of the US.  I'll talk about those as they come up in my narrative.  If the accident didn't take place in Hawaii, then some of this narrative will not apply.

I don't like the term "Dry Rot", because it implies something that isn't there - a "rotting" of the material.  While its true that rubber deteriorates over time, it isn't like rubber gets attacked by bugs like wood.  The properties of the rubber gradually change.

I prefer the term "weather cracking" which is more neutral and more descriptive.

Weather cracking can be an indicator of the state of deterioration of the rubber - but it is not a cause of a failure.

Also weather cracking is not a digital kind of thing.  There isn't a point at which it suddenly appears.  It gradually gets worse.  It starts as superficial and grows in both intensity and depth.  The dividing line between "good" and "bad" is not well defined and comes from experience.

So would a tire that has been judged to have "dry rot" have "weather cracking" 3 months earlier?  Yes.

How much difference?  Probably not a lot, unless there were drastic changes in either environment or operating conditions.

Should a tire that is 6 years old show some weather cracking?  Very likely.  Given that this is Hawaii, 6 years is about the time limit for tires.  So the inspector should have flagged the tires for their age.  

While it is gradually changing, it is not common knowledge for consumers that there is an age limit for tires.  It has become common knowledge for tire dealers - and yet, there are people in the business who either don't know this, or don't apply the principle well.  And in particular, age is an over riding factor and lack of weather cracking does not indicate a "good tire".

Nevertheless, tires less than 6 years old should not fail.  It would be good to get someone to analyze the tire, because some tire failures are road hazard related.

At this point, you can not eliminate either the tire manufacturer or the tire dealer from this.  Depending on what is found in the analysis, either or both could be pointed to as having some role in the accident.  

- BUT -  

The witness isn't helpful.  Tires don't just bend and explode on their own.  This sounds more like what one would see as part of a sequence of events involving striking an object in the road.  Again, an analysis of the tire would help establish this.