Originally the Metropolitan Transportation Authority, or the MTA, as immortalized in the popular folk-protest lament Charlie on the MTA[?].
See Boston/Transportation.
... is 2.86 and the average family size is 3.32. In the town the population is spread out with 24.7% under the age of 18, 7.4% from 18 to 24, 32.6% from 25 to 44, 23.2% from 45 ...