Arches National Park on Wednesday unveiled a proposal for a reservation system that it hopes will reduce the crush of visitors, but may irritate some who are unable to plan ahead.

Park officials emphasized the point of the plan is not to limit the number of visitors, but to spread visitation out during the course of the day and throughout the year. The plan would limit park entries during certain three-hour windows between 7 a.m. and 6 p.m. over the March-through-October high season.

“We would get more visitors in and they would have a better experience where they didn‘t have to fight to drive in and fight to find a place to park,” said park Superintendent Kate Cannon, who believe her proposal will enable Arches to handle 40 percent more visitors than the 1.6 million it received in 2016.

Such a “timed entry” system will not sit well with those who prefer being free to visit the park when they choose.

In September, after Zion National Park floated a similar idea, Reps. Rob Bishop and Chris Stewart sent Interior Secretary Ryan Zinke a letter, expressing their concerns and requesting a meeting with senior staff.

Francisco Kjolseth | The Salt Lake Tribune A long line of visitors stretches out along the sandstone as people make the three-mile round trip to one of Utah's most famous icons, the famed Delicate Arch in Arches National Park in late May.

In recent years, however, Arches has doubled the amount of parking at Devil’s Garden, Wolfe Ranch and other popular destinations and explored a shuttle system, but none of it has shown much promise for fixing the episodic congestion crisis that gets worse each year, according to Cannon.

“Reservations aren’t an idea that we love. It’s the only thing we really think is going to work at Arches,” she said. Something has to change if the park wants to fulfill it’s mission of accommodating the public and protecting park resources. On busy weekends, lines of cars back onto Highway 191 at the entryway north of Moab.

“When they get in the park, they breathe a sigh of relief, but when they get to where they want to go they can’t find a place to park. They circle, they circle. They go to the next place, they circle,” Cannon said. “We want people to come in and enjoy the place but we need to change the way we manage traffic.”

Her proposed plan would allow 2,006 vehicles over the course of the 11-hour reservation window. That number was set so that at any one time there would be 729 vehicles in the park, or 85 percent of its 857 parking spaces. But Cannon believes the park could handle up to 2,500 cars a day in optimal situations.

The National Park Conservation Association has endorsed the concept of timed entry, especially if the system can be adjusted as circumstances change.

“You will be getting information and using that to manage visitation,” said the group’s Southwest regional director David Nimkin. “There aren’t a lot of options. You can’t turn off this spigot.”

Arches visitation has grown by 90 percent in the last decade, growing more than four times faster than for the park system as a whole.

The plan is outlined in a draft Environmental Assessment, or EA, released Wednesday. A public comment period runs through Dec. 4 and the park will host an open house at Moab’s Grand Center, 82 N. 500 West, from 4 to 8 p.m. on Nov. 16. Comments can be submitted through the National Park Service’s planning web page or mailed to its Southeast Utah Group, 2282 S. West Resource Blvd., Moab, UT 84532.

Chris Detrick | The Salt Lake Tribune Visitors take pictures and hike around Delicate Arch in Arches National Park Saturday March 5, 2016.

This proposal is separate from the Park Service’s proposed $70 entry fee at Arches and 16 other busy parks. Cannon believes that fee hike would not have much bearing on her traffic-congestion plan, which is the fruit of years of studying various options that were ultimately shelved.

For nearly 20 years, Zion has used buses to shuttle millions of visitors up and down the narrow Zion Canyon. But such a system would be cost prohibitive for Arches, where the 16-mile entry road is much longer than Zion’s. A non-mandatory shuttle would cost $3 million per year and reduce vehicle traffic by at most 28 percent, according to the EA.

More parking is possible, but mostly in the form of structured lots that would be expensive.

“We will continue to add parking where appropriate, but the space is absolutely limited without degrading the park,” Cannon said. “Recreation is huge and growing. This isn’t going to go away.”

Under the reservation proposal, visitors would purchase their reservation on the recreation.gov website, which will be overhauled and under a new contractor by the time this system would be implemented next fall. The reservation, which would cost $1.37 to make, would not be needed to enter the park after 6 p.m. or before 7 a.m. or to visit during Arches’ “slow” season.

“We may overbook to fill all the spots,” Cannon said. The park would also hold some spots to release the day before or the day of the visit.

The Park Service has long required reservations for places that require ranger-led tours, such as the Washington Monument and Timpanogos Cave National Monument. Muir Woods National Monument outside San Francisco is also developing a reservation plan, as is Zion, Utah’s most crowded park poised to see a record 4.5 million visitors this year.