Police and security personnel were out early Thursday morning at University of Pennsylvania's Franklin Field preparing for the next three days.
About 15,000 people are expected to attend this year's event. Police say attendees should expect longer lines and tighter security in the wake of the Boston Marathon bombings.
Security is on the minds of longtime competitors like Allante Keels and Chelsea Delaney.
Keels explained the importance of the event, telling Action News, "Penn Relays is sort of like the Mecca for track and field. I mean, you have high school athletes, college athletes like us? as well as professional athletes. So, it's kind of like the center of the track and field world for this weekend."
People of all ages from all over the world will come to Franklin Field. Athletes will be permitted to have large bags that will be searched at a separate entrance - fans, however, cannot bring large bags, including backpacks or coolers.
Getting in this year could take a little longer. In fact public safety officials say to treat it like a trip to the airport.
But Delaney and Keels say the security won't break their strides, and officials want everyone to know the security is to make sure everyone has a fun and safe time.
"It's always good to up security just in case," said Delaney.
Maureen Rush, Vice President of Public Safety for the University of Pennsylvania, explained the objective is, "To make the spectators feel ? and the runners coming from all around the world ? to come here knowing we're doing everything possible to keep them safe. Number two, we're going to keep them safe by enhancing the security detail."