I'll say this about retreads...I don't know how common this is in other states, but going down the I-5 in the San Joaquin Valley in central California in the summer (routinely 100+ degrees), the sides of the road (and sometimes the highway itself) are littered with "alligators" that separated from the tire carcasses. Even with trucks doing 55 mph, the sun and the asphalt work together to get the tires so hot that the glue weakens...