HAMPDEN – Stretching 367 miles from New Hampshire to New Brunswick, Maine’s interstate highway sped through its 50th anniversary Thursday with no sign of pulling over.

With a red, white and blue cake and the unveiling of a commemorative sign, the Maine Department of Transportation marked the milestone with a short ceremony at the Hampden rest stop and visitor information center.

The Federal Highway Act was signed on June 29, 1956, by President Eisenhower, who said he was inspired by the mobility afforded by the German autobahn when he encountered it as a general during World War II.

Eisenhower’s “vision of linking the Atlantic, Pacific and all points in between with modern superhighways has resulted in decades of faster, safer travel for America’s citizens and commercial interests,” DOT Commissioner David Cole said in statement prepared for Thursday’s ceremony.

In 1957 the first stretch of the interstate in Maine was completed, running from Freeport to Brunswick.

Citing a Bangor Daily News article from 1956, Meg Lane of the DOT noted that it used to take a whole day of driving to get from Bangor to Portland.

The Maine interstate was built in unconnected chunks. A stretch of highway running from Bangor to Orono was completed in 1960. The section linking Bangor and Newport was finished in 1963.

Some eyebrows were raised in the mid-1950s when it was revealed that the route through Bangor would carve a path through the Roman Catholic Mount Pleasant Cemetery. But concerns subsided when Bishop Daniel J. Feeney said in 1956 that the church had “no objection” to the interstate running through an unused and “unusable” section of the cemetery. No opposition was expressed at a September 1957 hearing before the State Highway Commission.

When the section between Fairfield and Newport was completed in 1964, it was the final link connecting Bangor with southern Maine.

In 1994, the American Society of Civil Engineers declared Eisenhower’s highway system one of the “Seven Wonders of the United States.” The list includes well-known structures such as the Hoover Dam and the Golden Gate Bridge.

Many people take the interstate for granted, “especially those under 50 who don’t know what it was like before” it was completed, Cole noted Thursday.

Some $61 billion worth of goods flows through Maine every year, according to Cole. The majority of that sum, 80 percent, is shipped across Maine’s interstate.

“You couldn’t support an economy without an interstate,” he said.

Up-and-coming world powers China and India are both planning to construct highways, according to Jonathan McDade of the Federal Highway Administration.

Maine’s biggest industry, noted Cole, is tourism. If Maine didn’t have a way to move people from one part of the state to another quickly and cheaply, tourism would suffer greatly, he said.

Since funding for the interstate began in 1956, the population of Maine has increased 39 percent, Cole said. Miles traveled by automobile, however, have increased 288 percent.

Interstates are safer than other roads despite the higher speeds, according to the DOT. Railings, rumble strips, paved shoulders, gentler curves, multiple lanes, median barriers and the lack of intersections contribute to the safety.

Mile for mile, Maine’s interstate has about one-third the amount of deaths as the national average, McDade said.

Fifty years of service, however, has taken its toll on some sections of Maine’s interstate.

“Lots of bridges are getting to the age where they need to be replaced,” said Scott Leach, president of the Maine Better Transportation Association, an advocacy group that promotes funding for Maine’s transportation systems.

“I-95 just turned 50, and like all 50-year-olds, such as me, it’s showing some signs of age,” Cole said.