Sure thing! Cambridge Street has a long and fascinating history. It's been rebooted a few times in different eras.

Most recently, as part of the 1960s urban renewal project that razed Scollay Square and replaced it with City Hall Plaza, Cambridge Street was slightly moved and rebuilt from the ground up. The utilities underneath that you allude to are not from 200 years ago, but rather from the 1960s. There are complications that arise in any tunneling project, but as far as tunneling in "old Boston" goes, this is good as it gets. Basically, if we can't tunnel here, we can't tunnel anywhere on Shawmut Penninsula.