LANSING - Like children in an old television show, tourists crossing the Mackinac Bridge say the darndest things, according to the Mackinac Bridge Authority.

"What time does the bridge swing over to the island," is one of the most commonly heard questions by toll collectors, said Bob Sweeney, executive secretary of the authority.

In November, the bridge will celebrate its 50th anniversary, and its keepers will hear plenty of interesting, entertaining and sometimes just plain silly questions.

"When people cross the bridge, they don't realize they are still in Michigan, let alone the U.S.," Sweeney said. "They want a different exchange rate for their money."

Heightened passport rules for traveling between the U.S. and Canada have resulted in an increased asking of another question:

"Do you need to see my passport?"

Entering the Upper Peninsula is like entering a foreign or new world for some tourists.

"We have one collector who is American Indian and looks very much so," Sweeney said. "When people come across they will say, 'Look kids, a real Indian!' He really gets a good laugh from that one."

Construction began on the bridge on May 7, 1954, following years of debate on how to best cross the Straits of Mackinac.

Everything - from a tunnel to a series of causeways, tunnels and bridges going from Cheboygan to Bois Blanc Island to Round Island to Mackinac Island and finally ending in St. Ignace - before a single suspension bridge with two towers was ultimately chosen.

"The original concept showed two suspension bridges" end to end, said Sweeney. "There would have been four towers with three or four anchor piers."

Questions about nearby Mackinac Island also provide many humorous moments for toll collectors.

"How big is the parking lot on the island?" at least one tourist wondered, according to Sweeney.

"There is no parking lot on the island."

"Then where do I park my car!" a distraught tourist demanded.

Mackinac Island remains reachable primarily by ferry, and no motor vehicles, except emergency ones, are allowed on the historic site.

Contrary to popular misbelief, there is no one buried in the concrete of the Mackinac Bridge, according to the bridge authority.

Commonly told among schoolchildren, that story is about an ironworker who lost his footing and fell to his death. It's said he landed in newly poured concrete, where his body lies today, preserved beneath the bridge connecting the two peninsulas of Michigan.

While historians say no ironworker is encased in concrete, five people did die in accidents related to construction of the bridge.

One diver died when he surfaced too quickly, a wielder died when he fell into an underwater retaining structure, a worker fell from a short distance into the water and drowned, and two others fell 550 feet from a catwalk near the North tower, according to the authority.

Of the two workers who fell from the catwalk, one body was recovered immediately and the other was never found, it said.

Tolls have always been a staple of the bridge to offset the costs of construction and maintenance.

"I remember when the toll was 75 cents," is another frequent comment.

Funny, considering tolls were never that low, said Sweeney.

Opened on Nov. 1, 1957, tolls were set at $3.25 per passenger vehicle.

In 1961, tolls rose to 3.50 and again to $3.75, where they stayed until 1969, when the Legislature passed funding for the authority and tolls were lowered to $1.50 for a passenger vehicle.

The cost for traversing the bridge remained at $1.50 until 2005, when it was raised to $2.50, because of increased maintenance costs, Sweeney said.

The Mackinac Bridge is the third-longest suspension bridge in the world behind the Akashi Kaikyo Bridge in Japan at 12,826 feet between suspensions and the Great Belt Bridge in Denmark at 8,921 feet. Both bridges opened in 1998.

At 8,614 feet between suspensions, the Mackinac Bridge is the longest suspension bridge in the Western Hemisphere.

The total length of the bridge is 28,372 feet. It links Mackinaw City in the Lower Peninsula and St. Ignace in the Upper Peninsula.

At just over five miles, the bridge is long enough to cause some trouble for crossing motorists who fail to fill up their gas tanks before crossing.

"It happens every year," Sweeney said of motorists running out of gas. "It's really interesting how many we get. It's not a comfortable place to be broken down."

Because there is nowhere to go, bridge officials must go to the embarrassed motorists and bring them gas or tow them across.

Not all events that occur on the bridge are so negative, however.

One of Northern Michigan's largest events of the year, the Mackinac Bridge Labor Day walk, results in at least one person proposing marriage.

To keep the bridge looking pristine, workers spend countless hours and use myriad gallons of paint.

"Every year we use around 50,000 gallons for spot painting," said Sweeney. "We used to paint from one end to the other and it would take seven years, or 350,000 gallons of paint."

Of the paint used each year, 45,000 gallons of green is used on the lower sections and cables, while 5,000 of ivory is used on the structures.

Because of an $80 million maintenance plan, the 50-year-old structure is expected to have an infinite lifespan.

Everything from the steel structure below the deck to the joints holding the bridge together are slated for replacement by 2014, said Sweeney.

"A suspension bridge is like a rope bridge above a ravine," he said.

And like a rope bridge, it shifts, as much as 35 feet in high winds, resulting in wear and tear to components of the structure, according to the authority.

But don't worry, the bridge won't fall or tip over, the authority promises.