Most U.S. airports saw smooth operations as the new REAL ID requirement officially began on Wednesday.
Travelers without a REAL ID were still allowed through security but were given warning notices about needing proper identification for future flights.
The TSA handout explained that without a REAL ID or approved alternative, passengers could face delays or extra screening.
The Department of Homeland Security noted that 81% of travelers already have compliant IDs, helping avoid major disruptions.