The tickets. On the bus and on the subway (known in Boston as the “T”), they are accepted in only 1 of 4 possible senses. If you enter a ticket in the wrong direction, it is rejected. Already, a bus driver passed me through without paying because I dipped the card the wrong way the first time (nice trick, I know). When the amount purchased has run out, the temptation is to leave the ticket on the top of the gate as you pass through. I’m not alone. New York and DC have the same problem. I hear they plan to encourage re-use by introducing a plastic card instead of the paper ticket. That hasn’t happened in New York, however. People ditch the plastic cards, too.
rekha on the MBTA fare machines