The objectives of the project were to relieve highway traffic congestion, to reduce bottlenecks by providing additional crossings over the River and Harbor, and to reduce the accident rate. Congestion had been a problem for many years and accident rates were four times the national average, but community opposition had prevented the building of more highways in the city centre.
The idea of burying the Central Artery (Interstate 93) underground dates from a 1971 meeting between the mayor’s transport advisor, Fred Salvucci, and a highway contractor. Meanwhile, the business community was pushing for another harbor crossing to improve access to the airport. Salvucci was to become a key figure in the project’s evolution: as the Governor’s transport secretary in the 1980s he was involved in bringing the two projects together, providing a sufficiently broad base of support to proceed.
Official planning began in 1982, and environmental impact studies in 1983, with the Environmental Impact Statement/Report published in 1986. US Congress passed a public works bill securing funding for the project in 1987 and, although the bill was then vetoed by the US President, Congress eventually overrode the President’s veto.
Controversy began in 1988, when Salvucci’s choice of the ‘Scheme Z’ crossing of Charles River met with widespread criticism and opposition. A new ‘amputated’ version of Scheme Z was presented in 1990 and quickly incorporated into the Final Supplemental Environmental Impact Statement. A package of mitigation measures was announced and the main opposition group conceded.