PHILADELPHIA (WPVI) -- SEPTA is no longer allowing Regional Rail riders to buy tickets on the train if they're leaving Philadelphia in the afternoon.The Southeastern Pennsylvania Transportation Authority made the announcement Thursday.The new ticketing policy goes into effect Monday. The temporary change means that riders will have to buy tickets at ticket offices prior to boarding.The stations affected are Temple, Jefferson, Suburban, 30th, & University City Regional Rail Stations during PM travel hours of 3 p.m. to 6:30 p.m.The procedures for AM, Evening, and Weekend fare collection will not change."Fare Collection personnel will be stationed by each stairway. Once the fare has been validated or collected, customers will be able to proceed directly to the train platform and all stairways will be open," SEPTA says.The agency goes on to say, "Cash will not be accepted for pre-boarding payment and on-board fare payment or collection will not occur at these Stations. Customers with cash must purchase a ticket at the Station Ticket Office before going to the stairway fare line."SEPTA officials say the change was spurred by the scheduling issues created by the loss of more than a 100 rail cars due to a structural defect.----The Associated Press contributed to this report.