The road to the Cadillac Mountain summit in Acadia National Park was closed 49 times this summer because of traffic congestion, emphazing the need for more visitors to use the park’s shuttle bus system and providing key data for a new transportation plan, according to a park spokeswoman.

Christie Anastasia, public affairs specialist for Acadia, released statistics of the temporary closures to incoming motor vehicles on the Cadillac Mountain summit road that occurred between June 28 and Sept. 4.

The statistics show that 11 of the closures occurred during sunrise and 15 likely during sunset. She said the Cadillac Mountain summit was temporarily shut to incoming traffic seven times during the Labor Day weekend. When the road is shut, the entrance at the base of the mountain is blocked and rangers are stationed there.

While the fare-free Island Explorer does not stop at the top of Cadillac, the tie-ups on the mountain are a sign of the heavy use of motor vehicles inside the park, along with tight parking throughout the park during busy times. The large parking lot at Jordan Pond, for example, was also closed temporarily on Labor Day, causing many motorists to drive around looking for spots or to park illegally.

“I do think It underscores the importance of the Island Explorer,” Anastasia said. “You don’t have to worry about parking your car. You get on a bus. Someone else drives. You can look out the window and enjoy the scenery.”

The statistics also help in the completion of a new transportation plan. By the end of this year, the park might release a draft Environmental Impact Statement on the plan and then launch a new round of public comments. The park is considering preliminary ideas such as a reservation system for motor vehicles to park at Jordan Pond and to drive up Cadillac, the tallest mountain on the U.S. Atlantic coast with spectacular views of the Porcupine Islands and Frenchman Bay.

“The fact that we are collecting the data on the closures helps us understand parking management strategies as part of that transportation planning process,” Anastasia said. The park’s dispatch office is tracking the closures in a spreadsheet, she said.

Solar eclipse shut Cadillac Mountain summit road for 90 minutes

Of the 49 closures due to congestion, the shortest was 13 minutes and the longest was for about 90 minutes during the solar eclipse on Aug. 21.

The number of visitors to Acadia so far this year is about the same as last year, when the park drew 3.3 million visitors during the centennial celebration, Anastasia said.

“It is conceivable we are on track to hit the same number, maybe a little more or a little less. Weather is a big factor in visitation here.”

This year, new visitor service assistants are working with Friends of Acadia Summit Stewards to monitor traffic at the Cadillac Mountain summit and help park rangers determine when conditions warrant the temporary closure of the peak to further motorists, she said.

Generally, the summit road is closed to incoming cars when traffic is bumper to bumper from the parking lot at the peak to the Blue Hill Overlook, located about a quarter of a mile from the summit lot.

The park this year has a formal system where certain traffic conditions trigger a closure of the Cadillac peak to incoming motorists, mostly because it might no longer be safe for people or it might impede emergency responders in case of an accident or medical issue, Anastasia said.

“That’s part of trying to pay more attention to what is going on there,” she said.

Last year, the Cadillac Mountain summit was closed to traffic 12 times by the park, John T. Kelly, management assistant for Acadia, said late last year.

Over the Labor Day weekend, the closures on Cadillac included three on Sept. 2, each for about an hour, one on Sept. 3 for a little less than an hour and three on Sept. 4, each for about 30 minutes, Anastasia said.

The road to the Cadillac Mountain summit was also shut temporarily seven times during two days of the July 4 weekend.

The road to the Bass Harbor Head Lighthouse was also closed for just three minutes on Sept. 3, she said.

The Jordan Pond House parking lot and the nearby Jordan Pond lot with access to hiking trails and boat ramp were also jam-packed during the Labor Day weekend.

On Labor Day, reporters overheard one driver pleading with a Jordan Pond House parking attendant to let him park illegally on the grass. “I’ve been driving around for 30 minutes and I can’t find a place to park,” the driver said.

Maybe the tourist didn’t know that he could have taken an Island Explorer bus directly from Hulls Cove Visitor Center to Jordan Pond House, and saved himself the half hour of circling around.

“It is a very loved park,” Anastasia said. “People want to enjoy it. That is a great problem to have. So many people love the park they want to come here.”