When SEPTA installed readers for its new Key fare card on all its buses this summer, they were put only at the front of the bus, making all-door boarding an impossibility fleet-wide for now. This Sunday, though, SEPTA will begin the Roosevelt Boulevard "Direct Bus," an effort arranged by the city and SEPTA to create something like express bus service along one of Philadelphia's busiest corridors. The idea is to make that service frequent and reliable.