As of 2017, King County Metro operates the 10th largest fleet of buses in the United States, with a total of 1,540 buses. Upon taking over transit operations on January 1, 1973, Metro used buses acquired from predecessor agencies Seattle Transit System and the , still painted in their original colors. Metro acquired the 91-bus fleet of the Metropolitan Transit Company in December 1972 at a cost of $2.75 million. The first fleet of new 40-foot (12 m) buses ordered by Metro arrived in June 1976, consisting of 145 diesel coaches manufactured by AM General. In 1978, Metro became the first large transit agency in North America to introduce articulated buses to its fleet, which required some bus stops to be rebuilt to accommodate 60-foot (18 m) coaches. The fleet of 151 buses were manufactured b