Incentives matter: petrol prices file

An article at Boston.com notes

The number of T [public transport] trips rose from 27 million in February 2007 to nearly 30 million in February 2008, up more than 11 percent for the month, Massachusetts Bay Transportation Authority officials said. The numbers were up about 5 percent for January. Combined, the average increase is 8.3 percent.

The rising MBTA numbers follow a national trend. More Americans rode public transportation last year than at any time in history, according to the American Public Transportation Association, ...

Why? According to the article

The high cost of gasoline has helped fuel a sharp increase in MBTA riders over the first two months of the year and a decrease in the number and length of traffic jams, according to T officials and traffic specialists.