Amtrak, along with SEPTA police, Philadelphia police and federal authorities were conducting Operation Rail Safe along the Northeast corridor.
Amtrak made it clear this is not a response to a specific threat or a reaction to the travel advisory for Americans in Europe.
"This exercise was planned in advance. It's coincidental that it occurred during the European threat. There is no connection," said Chief John O'Connor of the Amtrak Police.
The exercise is most definitely terror related, however. It's an effort by Amtrak to show that it is capable of responding to credible threats or actual attacks.
More than 60 federal, state and local agencies are participating in this system wide effort.
Police dogs were sniffing bags for the possible presence of explosives, while officers were randomly swiping bags for evidence of the chemical components of bombs.
There are also things going on behind the scenes like stepped up undercover patrols on the trains as they travel between stations.
With 27 million passengers a year, Amtrak is an inviting target and this exercise is intended to reassure the passengers.
"We don't want them to be alert. If they see something that looks suspicious, let somebody know," said O'Connor. "If you see something, say something."
For some passengers, it's a bit unnerving to have a K-9 dog sniffing their bags.
But most say it gives them a reassuring sense of security, like Jane Bagley who's taking her daughter to tour some schools in Washington.
"Just knowing there's a greater presence of security gives me a higher level of comfort," Bagley said.
That's one of the intended effects of this exercise. The other is to test the capabilities of the agents involved and their ability to coordinate a massive interagency effort in the event of the real thing.