The PA Turnpike officially opened for business on October 1, 1940, and spanned 160 miles from Carlisle to Irwin. Planners originally predicted that 1.3 million vehicles would use the PA Turnpike each year, but they underestimated. A total of 2.4 million vehicles traveled it annually. Today, there are 550,000 daily travelers.

Check out this interactive timeline for more facts.