the washington metrorail system is the second busiest commuter rail system in america, carrying as many as a million passengers a day. it carries the equivalent of the combined subway ridership of bart in san francisco, marta in atlanta, septa in philadelphia each day. but more than three decades after the first train started running, the system is showing severe signs o of age. 60% of the metro system is more than 20 years old. the cost of operations, maintenance and rehabilitation are tremendous. this is not the only