Travelers flying within the US starting Wednesday must use a state-issued ID that is “REAL ID compliant” or be subject to further screening. Things seemed to be operating relatively smoothly at a sampling of US airports Wednesday morning.

SAN FRANCISCO (AP) — Most airports around the United States operated smoothly as new REAL ID requirements took effect Wednesday because travelers without the updated document were still allowed to move through security easily.

After years of delays, the REAL ID deadline officially arrived, and travelers across the country are navigating new rules and last-minute surprises.