DENVER—An airline unveiled a new boarding tier Friday for passengers who rise from their seats the moment a gate agent approaches a microphone.

Called Already Up, the $49 upgrade gives customers permission to occupy the space directly in front of the gate before their group has been called, formalizing a service they had been providing themselves for years.

"We listened to our customers," said airline spokesperson Melinda Shaw. "We couldn't see the customers who stayed seated."

Members may stand in either of two lanes: Not Yet and Also Not Yet. Both merge into a single point where a person trying to board must ask whether anyone is actually boarding.

Frequent flyer Thomas Heller praised the tier for recognizing his loyalty. "I've been standing here since Zone One," he said. His ticket was for Zone Six and a different gate.

Gate agents will continue asking passengers to keep the area clear. The request now serves as the invitation to activate Already Up benefits.

Families traveling with small children may board early after navigating the premium passengers, whom the airline describes as an interactive obstacle course.

Shaw said the program would improve efficiency by allowing staff to identify difficult passengers before takeoff. Customers who remain seated will be charged a $12 Cooperation Recovery Fee to offset the cost of being easy.

The first Already Up flight boarded in 58 minutes. The airline called it a successful launch, noting that every passenger had been ready for most of an hour.