Amtrak Ridership

Counterterrorism experts have renewed calls to tighten security on America’s mass transit lines following two would-be terrorists’ foiled plot to blow up a Toronto passenger train.

The alleged plan to attack Canada’s transit system has shed light on the vulnerabilities that still exist in America’s commuter system and the challenges involved in keeping it safe for travelers.

“The millions of Americans who take public transportation need to be assured that everything possible is being done to ensure their security and safety,” American Public Transportation Association President and CEO Michael Melaniphy told FoxNews.com on Monday, adding that federal funding should be increased.

Security analysts note that the very nature of public transit systems makes them hard to defend because of their open architecture, multiple access points and heavy volume of passengers. But a string of recent plots, including the latest out of Canada, underscore the need to make changes.