Boston that people talk about is really Boston and surrounding cities, much like New York City is made up of the 5 boroughs with Manhatten being New York County, Boston proper includes a few different cities inside of it like Mattapan, South Boston, Roxbury and the Greater Boston area includes Somerville and Cambridge. Many people outside of NYC would easily confuse Long Island as being part of NYC since it's part of the metro area.

Ironically, part of the reason traffic in Boston is so poor is due to not wanting to destroy poorer areas when roads were being built.