It could be months before the area settles into a "normal" traffic pattern, said Washington County Engineer Terry McGee.
For now, many shoppers are curiosity-seekers and there is more construction traffic as the second phase of the outlets gets ready to open this fall, McGee said.
After the newness of the shopping center wears off, engineers will take a closer look at the traffic to see if the timed signals on Sharpsburg Pike need to be adjusted, McGee said.
At a nearby Burger King restaurant, business started increasing a month before the outlet center even opened as construction crews and new outlet center workers placed large takeout orders, said Keith Boring, Burger King manager.
Boring estimated that the outlet's presence has increased sales 20 percent to 30 percent.
"We're really happy with them," he said.
The outlets also have brought more people to a nearby Snax/Shell convenience store, said Assistant Manager Alvina Pickett.
Although shopping and historic sightseeing may not seem to go together, Antietam Battlefield Superintendent John Howard said he expects more visitors because of the outlets.
Both are family activities and Prime Outlets has been promoting the county as a tourist destination.
But residents near the outlets feel like they're paying a price for the outlet center's success.
When John and Virginia Harries moved into the neighborhood 44 years ago, they could look out their window and see cows grazing.
Now, the West Oak Ridge Drive couple's home is surrounded by development.
Their backyard overlooks the outlet center and when they sit on their front porch their voices are nearly drowned out by traffic noise.
The couple has turned down offers to sell their home.
"We're far enough away. I'm not going to give up my house yet," Virginia Harries said.
Local police agencies said the outlet center hasn't created any major traffic tie-ups.
A new signal at the Sharpsburg Pike entrance plus extra lanes seem to be handling the extra traffic, said Maryland State Police, whose local barracks are practically next door to the outlet center.
"We thought, honestly, it was going to be a big headache. And it may turn around to be a big headache," said Sgt. Mark Knight of the Washington County Sheriff's Department. "So far we're real satisfied."
The Funkstown Volunteer Fire Co. had at least six calls for service at the outlet center in the first two weeks, said Chief Kyd Dieterich.
There was one accident in the parking lot, two ambulance calls and three false security alarms, he said.
That may not seem like a lot, but over time the outlets and other growth in the area will have an impact on the department, which is hiring its first paid driver, he said.