Interstates

Thanks to 15,000 workers from 155 contractors in 18 different states, it took just 23 months and five days to complete the Pennsylvania Turnpike following the formal groundbreaking on October 27, 1938. At the project's peak there were over 50 paving units laying up to three-and-a-half miles of concrete a day.
Hobby News

Pennsylvania turnpike paved the way for today’s interstates part II