The red line was the last of the MBTA lines to be created, originally placed only in central parts of Cambridge in 1912. For several decades after the addition of transit nodes along the line leading to Dorchester, the line was known as the Cambridge-Dorchester Tunnel. By the 1980s, the line had expanded both north and south, and by the late portion of the decade, the red line was complete with all of the stops that we see today. It runs from Cambridge and Somerville, through downtown Boston, and into Dorchester, Quincy, and Braintree. In 2013, there was an estimated 217,329 daily entries into a transit stop on the red line on a typical weekday.