Originally Posted by JohnsD90
just because you bought them new doesn't mean they are any safer, those tires could be up to 5 years old!
Granted, there are cases of newish tires going bad e.g. Firestone, years ago. However, unlike tires you get new where you know the history of the carcass (likely good, but sometimes bad), with retreads the history of the carcass is entirely unknown (always a bad thing in my book). A 60 sec inspection of 4 tires is unlikely to reveal internal separation of the carcass/retread.
As mentioned previously, the use of redundancy at each corner through tandem axles or dually set ups partially mitigates the inherent risk of tire failure. Therefore a blow out at speed for a big rig is less likely to result in catastrophic failure, unlike a four wheel vehicle. To each his own, but don't pretend that retreads are equivalent to quality new tires.