IAH Subway or Skyway: Which train should you take?

The right train depends on one important question: Have you passed through security?

Aug 30, 2025

George Bush Intercontinental Airport (IAH) has two free trains connecting its terminals: the underground Subway and the above-ground Skyway.

Use the Subway before security. Use the Skyway after security.

Connecting passengers who have already cleared security should use the Skyway. Leaving security to ride the Subway would require passing through a TSA checkpoint again.

Take the Subway when:

• You have not passed through security.
• You are meeting or dropping off a traveler.
• You are traveling to or from the Houston Airport Marriott.
• You want to explore pre-security restaurants, shops or services.

Take the Skyway when:

• You have already passed through security.
• You are connecting between flights.
• You need the fastest route between terminals without leaving the secure area.

Both trains serve Terminals A, B, C and D/E. Only the Subway serves the Houston Airport Marriott. Follow airport signs to the system that matches your location.