ATLANTA — Fast moving airport security lines at the start of the Memorial Day weekend could bode well for return travelers Monday.

Travelers reported moving quickly through airport checkpoints Friday after authorities opened extra screening lanes and used bomb-sniffing dogs to give some passengers a break from removing their shoes.

“Wow. I mean, wow,” said Mike Saresky, who flew into Chicago from Philadelphia, where he breezed through airport security in 12 minutes and got to leave his shoes on. “I thought it was going to be a lot worse.”

The extra dogs were concentrated at the nation’s largest airports, but they were not used for all screenings, meaning that many travelers still had to observe the usual procedures.

But as the busy summer travel season kicked off, the federal Transportation Security Administration tried to offer travelers some relief after weeks of slow-moving lines blamed on an increase in the number of air travelers and a shortage of TSA security officers.

A TSA spokesman said the extra dogs would remain well beyond the holiday.

At Hartsfield-Jackson Airport in Atlanta, known as the world’s busiest, all 16 security lanes at the main checkpoint were open Friday morning as a bomb-sniffing dog and its handler walked among waiting passengers. Wait times were slashed to less than 15 minutes, compared with backups of nearly an hour in recent weeks.

AAA predicted 2016 would have the second-highest Memorial Day travel volume on record and the most since 2005.