Most of Boston seems doable for car-free too, but I don't know if the public transportation can handle it. It's already taxed at rush hour and other peak times. I can't imagine everybody could get to work on time if everybody had to use it without major skewing of some schedules.
It seems like a strong telecommuting infrastructure and culture should be a part of this.
Public transit in Boston is already choked at rush hour, and badly in need of repairs (including complete fleet replacements for two subway lines, now scheduled to start in a couple of years) -- witness the total breakdowns last winter, which had some lines out of service for weeks.
And witness the repercussions. On the third day of the crisis, the Red and Orange lines were out, and a lot of people who normally came on them, drove instead. The result was that Cambridge was utterly crippled with traffic. On my way back from Kendall to Medford, I walked, and I got home earlier than anyone I know.
It seems like a strong telecommuting infrastructure and culture should be a part of this.