An armed agent pulling customers aside to a security area in U.S. train stations on the East Coast has become a standard Amtrak security measure.

Since February, armed counterterrorism agents have been working at Amtrak stations most vulnerable to a terrorist attack. They randomly scan passengers' bags with explosive detection equipment, USA Today reports.

The scanning, which started in February, takes about 15 seconds. This fall, Amtrak will expand its multi-million dollar screening program to the West Coast.

Passengers don't need to arrive earlier nor have any trains been delayed.