The countdown to holiday cheer is on, and inside U.S. Post Office facilities, the rush is already well underway. As millions of Americans ship gifts across the country, the Postal Service says it’s prepared for the seasonal surge.

USPS Strategic Communications Specialist Xavier Hernandez says mail and packages are moving quickly through the system.

“We’re getting that mail in, getting those packages in, and getting them out for our customers on behalf of the big guy, Santa,” Hernandez said.

USPS officials credit a recent $40 billion investment for smoother operations this year. The agency says its package-handling capacity has increased by 50 percent, just in time for the holiday rush.

Customers are already noticing the difference.

“I was worried about my package getting there on time,” said Sue Carroll, a USPS customer. “But I was really surprised, it’s going to get there in two days, so I’m really happy about that.”

Behind the scenes, the improvements include 36,000 new vehicles, 14,000 seasonal hires, and more than 600 new machines nationwide. But USPS says its biggest strength remains its workforce, people like Alvaro Lopez, a letter carrier who has spent the past 42 years delivering mail.

“I wake up every morning, and I’m the first one here - and the last one to leave,” Lopez said. Lopez says the long shifts and heavy workload don’t slow him down, even as he sorts through piles of letters and packages each day.

“The people out there, they bring me up,” he said. “It’s something that keeps me going.”

And he’s not ready to stop anytime soon.

“I know one day it’s going to stop,” Lopez added. “But I’m aiming for the 50 years now.”

USPS officials say carriers like Lopez, along with thousands of seasonal workers, will be out in full force as the holiday deadline approaches. For those still wrapping and shipping gifts, the Postal Service says Saturday, December 20th is the last day to use Priority Mail Express to ensure delivery by Christmas.