Factors that led to the beginning of the project

• Beginning in the 1950s, an 1.5 mile long elevated highway section ran straight through the city, marring the historical aesthetic of the city.
  
• The project to construct the elevated highway displaced more than 20,000 people and demolished more than 1,000 structures.
  
• The Central Artery, completed in 1959, was designed to carry 75,000 vehicles a day.
• 190,000 vehicles per day by the mid-1990s
• The structure was beginning to crumble as the year 2000 approached, it was clear that a new system was needed.