Cleveland, like many American cities, experienced its heyday of streetcar transit lines in the early decades of the twentieth century. Many Clevelanders still fondly recall their trips downtown aboard the creaking, groaning streetcars that plied the city's major thoroughfares. While streetcars formed the backbone of public transit in the first half of the century, in the second half, buses and rapid trains became common. The Greater Cleveland Regional Transit Authority formed in 1975 through the merger of the Cleveland Transit System and the Shaker Heights Rapid Transit and also assumed control over several suburban bus systems. RTA spearheaded the federally funded Euclid Corridor Transportation Project, the culmination of decades of attempts to introduce a high-speed transit line on Euclid Avenue.