It's not the volume of packages that bothers UPS driver Andy Kulp this time of year. Nor is it making 267 stops during a 13 1/2-hour workday, keeping track of the hundreds of small packages emblazoned "Amazon.com" or carrying 50 pounds of dog food to a house because Petsmart.com has a special offer going.

There's only one thing that gets him down: the office Christmas parties. When Kulp brings gifts to an office where workers are celebrating the holiday season with cookies and cake and punch and other treats, they always invite him to join the party. But he has to dash out the door--too many other deliveries to make--and he feels bad about turning down their hospitality.

"That's what hurts your heart," said Kulp, 37. "They're having pizza, and they say, 'Come on Andy, have some.' And I say, 'No, I can't stay.' "

Aside from that, Kulp doesn't mind the frantic Christmas pace. He gets plenty of overtime pay, and his three years as an Army paratrooper help him deal with the stress. It's also useful to remember a little UPS Zen, he says: "You just take it one stop at a time."

Kulp, who lives in Annapolis with his wife and five children, has been delivering packages on the same route in Southwest Washington for the 13 years he's been with United Parcel Service of America Inc.

Tuesday was the day he made 267 stops and worked from 7 in the morning until 8:30 at night, compared with his typical workday of eight hours and 135 stops during the rest of the year. Yesterday was only slightly less busy. He made about 200 stops at homes, offices and industrial sites.

That doesn't include the times when Kulp went back to a house later in the day because no one was there to accept delivery on his first visit. UPS doesn't have a rule on this, leaving it up to each driver to decide whether to make a return trip.

"During Christmas, I'll always make an extra attempt," Kulp said. People are working, or they're out shopping for even more presents, he said. "I have a family and I have kids, and I know you can't do everything at once."

The UPS driver is perhaps the closest thing to a real-life Santa Claus. The company delivered 18 million packages around the world Friday, its busiest day of the year, compared with a normal daily total of about 12.5 million packages.

Internet shopping has brought UPS a surge in new business. It shipped 55 percent of the Christmas purchases made via the Internet last year, while the U.S. Postal Service shipped 32 percent and Federal Express Corp. 10 percent, according to Zona Research, which studies online commerce trends. Online orders have helped UPS throughout the year and helped generate the company's 28 percent growth in net income for the three-month period ending Sept. 30 compared with the same quarter a year ago, UPS spokesman Steve Holmes said.

Kulp and other drivers say they might as well be Santa, for all the excitement the uniform and truck elicit in grown-ups and children alike.

Tyrone Pittman, who helped load Kulp's truck yesterday morning, makes deliveries in the evening to Bolling Air Force Base. "You should see the kids running after the truck," said Pittman, 35, who lives in New Carrollton.

Pittman said that sometimes when he goes to the door of a house, he finds parents trying to block the children's view so they won't get an early clue about what's going under the Christmas tree. "They're giving you signals like, leave it on the side of the house or leave it around back," he said.

Kulp's first stop yesterday was at the Capitol Hill home of Bruce Robey, who publishes the Voice of the Hill newspaper and received a box of oranges and grapefruits. Kulp "has been here as long as I can remember," Robey said. "He came with the house."

Then it was on to a rock quarry and salvage yard for a shipment of machinery. Even at Christmastime, there are still the deliveries of tires and iron bars to industrial clients. "It's a little bit of everything. I never get bored," Kulp said.

Shortly before 10 a.m., he was at Coast Guard headquarters, whipping through the corridors with a handcart full of office supplies. He worked quickly but still managed to squeeze in some friendly conversation. At one office, he spent a few minutes talking with Petty Officer Kishea Brown about the Bible. She wondered what part of the Bible referred to being "in the world but not of it."

"You might look in First John for that," Kulp said. A few more moments of chatting, then an apology from Kulp: "I've got to roll."

Dorothy M. Hall, a Coast Guard worker whose son, Ivan Hall, is also a UPS driver, said Kulp is friendly and outgoing day after day. "I've known him ever since he's been on the route," she said. "With the personality he has, there's no way to avoid him. He's been like that since Day One when I met him. The same Andy."

Kulp says it's the encounters with customers that keep him going during this hectic time.

"Whenever I hit the wall, I just turn myself off from my job and turn myself on to the people," he said.

CAPTION: UPS driver Andy Kulp stacks up deliveries near the Coast Guard in Southwest Washington, where he has worked the same route for 13 years.

CAPTION: Kulp greets longtime friend Sean Morgan, a Coast Guard security guard, as he arrives with the day's goods. Kulp bestowed normal and holiday packages on hundreds of addresses yesterday.

CAPTION: At a UPS warehouse in Landover, Selene Jackson, left, and Judy Monson decipher unreadable addresses. The company delivered 18 million packages Friday.