In 2000, the estimated cost of the Central Subway project was $530 million. By 2001, the cost had risen to $647 million and completion was projected for 2009. When construction began in 2012, the cost had reached $1.6 billion. When the main contract for Central Subway construction was awarded in May 2013 to the lowest bidder, Tutor Perini, the $840 million contract was up to $120 million over the budgeted amount, which took up nearly two-thirds of the entire project's contingency.