PITTSBURG, N.H. – The government has gone to extraordinary lengths to increase security along the Canadian border since the Sept. 11 terrorist attacks, but life continues as usual for most of New Hampshire’s northernmost residents.

Visiting Canada for an afternoon of shopping or an appointment with the dentist still are relatively easy trips. But those traveling through the main checkpoint on the road from Canada to New Hampshire now see U.S. customs agents with radiation scanners to check for nuclear material and X-ray machines to search for bombs and stowaways. Agents also can drop newly installed gates across the road in case of emergency.

Raymond Prehemo of Pittsburg, a longtime local trucker who crosses the border two or three times a day with loads of lumber, now has his truck searched more often than not.

“They know me,” he said last week. “But it’s their job.”

In Pittsburg, population 800, crossing into Canada is a routine trip for many residents. There’s an ATM, but no bank, in town. There are no shoe stores or furniture shops or clothing stores. The general store stocks staples such as milk, but for most groceries or lower prices, residents must leave town.

When New Hampshire residents cross the Canadian border, and when they return, they now face more scrutiny. Canadian customs agents, residents say, ask where they are going, why they are going and how long they will stay. They sometimes ask for photo identification.

Prehemo says agents look under the hood of his rig and check the sleeper compartment when he stops at the border. They run angled mirrors beneath his truck to check for anything that might be fastened to the undercarriage.

After Sept. 11, U.S. Customs has hired more agents and is using more sophisticated equipment to tighten national security, according to Fred Chenevert, supervisory customs inspector. Those agents are trying to balance the need for increased security with the need to keep tourists and trade moving quickly, he said.

“In the world of commerce, delay costs money,” Chenevert said. “With tourism, we don’t want to be so unfriendly people will just stay home, but at the same time we need to know who we’re dealing with.”

All checkpoints, some of which once closed at night, now are kept open around the clock and staffed by at least two agents, he said. Agents are equipped with radiation pagers that fit in the palms of their hands. They scan travelers with the pagers to check for radiation associated with a small nuclear device; a low-digit reading indicates that someone has had radiation therapy, Chenevert said.

“But if it’s 6, 7, 8, it’s big. It’s hot,” Chenevert said.

The customs service also uses a mobile X-ray machine that can scan an entire vehicle for signs of large, solid objects that might be explosives or for the shapes of people hiding inside. The ports of entry also are equipped with surveillance cameras – some hidden, some not – to catch the license plate numbers of cars that drive through.

The U.S. Customs Service’s authority ends at the official border crossings, however.