Budd–Michelin rubber-tired rail cars remained obscure in comparison with other competitors for the title, such as the "Pioneer Zephyr" and Union Pacific's M-10000. Rubber-tired rail cars achieved greater success in France, and similar rubber-tired subway cars have been adopted in Canada and Mexico as well as on numerous systems in Europe. During the 1920s, the American Budd Company, at the time a relatively obscure auto-frame supplier, developed an extensive working relationship with the French firm Michelin, which was best known for its tires. In 1929, Michelin built its first rail car, and by 1932 nine of its cars were in operating service, all of
Yaroslavl Synthetic rubber mass production in factory "SK-1", the reestablishment of domestic production facilities for the production of automobile and aircraft tires in the 1928-founded Yaroslavl Tyre Factory, and the opening of the rubber-asbestos combined works in 1933. In addition to all this, the Yaroslavl Automobile Works (founded 1916) continued to produce vehicles, including a number for the municipal transport administration of Moscow, well into the 1930s. During the years of World War II, Yaroslavl managed to escape the prospect of a German occupation of the city, since the Wehrmacht did not manage to break through the Soviet defense lines surrounding