Fourteen years ago, the $80 million Anton Anderson Memorial Tunnel opened for the public to drive cars, motor homes and trucks hauling fishing boats between Portage and Whittier. Despite a toll-free tunnel the first year, the state overestimated tunnel traffic, and its financial prospects seemed questionable. But more than a decade later, traffic through North America's longest tunnel has finally picked up to the point the state is earning a profit.

Facility manager Gordon Burton credits the uptick in traffic to Alaska's slow but steady acceptance of the one-of-a-kind tunnel. He said it took time for people to accept the tolls, which range from $10 to $300, depending on the mode of transportation. Some 83 percent of the vehicles taking to 2.5-mile journey are "Class A" vehicles, largely passenger vehicles not pulling a trailer, according to the Department of Transportation. As expected, May through September bring the highest revenue as fisherman, boaters and tourists flock to Prince William Sound.

Last year, the tunnel brought in more than $1.7 million, just $200,000 less than its peak in 2005. Traffic has ramped up from 172,986 trips in 2001 to 234,738 in 2010 -- a 36 percent jump. Tunnel revenue backs the maintenance of the tunnel, pays to clear snow and help train every tunnel employee become a certified firefighter, said Burton.

The unique passage wasn't always so popular.

"At first," Burton said, "people were a little resistant. Even after a year of no tolls, people still weren't sold. We initially saw a dip in traffic, but then it came back up."

Despite the high cost of taking the train to Whittier, people missed the nostalgia of it and Alaskans were unfamiliar with paying tolls for any road. Whittier residents feared that easy access would bring crowds and chaos.

"The town wasn't ready for it," said Charlie Eldridge, a resident since 1991. "We didn't have a lot of businesses and we had no public restrooms."

In the fall of 2000, Whittier residents expected their bathrooms to be overrun, parking lots to be full and traffic to be snarled once the tunnel opened. But then tunnel manager Greg Hall told the Anchorage Daily News that far fewer people used the $80 million tunnel than projected. Hall said Whittier didn't have enough money to promote the unique tunnel well, and doubts persisted about whether the tolls would stifle growth.

But by 2003, the tunnel was making $1.2 million in revenue. And like Whittier has always done, the town adapted to change.

Read more: As traffic grows, Whittier tunnel flourishes during summer months

Correction: A photo caption in this slideshow initially stated that the safe rooms inside the Anton Anderson Memorial Tunnel had never been used. They had previously been used in one instance when a school bus broke down inside the tunnel.