Budd–Michelin rubber-tired rail cars which featured innovative and distinctive pneumatic tires. The company claimed that its application of tires on its rail cars afforded both a substantially more cushioned ride and increased the cars' traction by 35%. The design of Michelin's tired wheels included an aluminum safety ring and a flange that were only used in the event of a puncture or other type of tire failure; during normal operation, only the rubber tire made contact with the rail. Inspired by Michelin's success, the Budd Company set its sights on marrying the new rubber rail tires with its shot-welded, stainless-steel carbodies; it had developed
Crumb rubber PAHs were found to be elevated as well. The levels of most of these compounds were higher than background but were below levels regulated in waterways for environmental protection. Crumb rubber Crumb rubber is recycled rubber produced from automotive and truck scrap tires. During the recycling process, steel and tire cord (fluff) are removed, leaving tire rubber with a granular consistency. Continued processing with a granulator or cracker mill, possibly with the aid of cryogenics or by mechanical means, reduces the size of the particles further. The particles are sized and classified based on various criteria including color (black only