While advising that it would be very difficult to hold the line, B/PB worked aggressively with MHD and MTA to recommend and implement savings and cost containment measures necessary to meet the state's objectives. By 2000, however, project scope changes, contractor claims, rising construction costs, and changes in allowable accounting practices made it impossible for MTA to maintain its zero-budget-growth mandate. MTA's chairman announced a revised cost estimate of $12.2 billion (including inflation). The new figure proved highly controversial, and various public officials as well as the media moved quickly to assign responsibility for what was widely termed a "cost overrun