By Matt Carroll, Boston Globe | Nov. 24, 2011

The number of cars per 1,000 residents is highest in many summer communities, which makes some sense. People who own vacation homes in those places, such as Aquinnah and Chilmark, may not be residents, but still might register cars there. That pushes up the number of cars against the number of residents. Low communities include urban areas such as Lawrence and Boston. The data, from the Department of Revenue, is for 2010.