Tolls, ride sharing apps, car pooling, avalanche sheds and a visitor center are among the key recommendations offered by a team of University of Utah engineering students hoping to solve the growing traffic nightmare in Little Cottonwood Canyon.

At least 2 million people visit canyon each year, leaving the ever-popular recreation area hopelessly congested on peak days and an ever-growing burden on a fragile alpine environment that is a key water source for Salt Lake City and home to two of the nation’s top ski areas, Snowbird and Alta.

With no room for more pavement in the narrow canyon framed between soaring granite walls, solutions will require smarter use of existing parking and roadways, the U. team leader Savanah Whitaker told an a packed audience at the Marriott Library Thursday.

After a semester studying the canyon’s traffic, the 17-member group compiled a $200 million list of recommendations.

They include graduated tolls that encourage car pooling and other steps to increase vehicle occupancy; encasing the road in sheds so traffic can flow during avalanche control operations; a visitor center at the canyon mouth; increased use of transit; and technology to inform drivers about available parking and connect them with people who need rides.

Little and Big Cottonwood canyons combine for 3.7 million annual visitors, with winter growth projected at 2 to 3 percent a year and 5 percent in summer.

“The fact that visitation is comparable to Zion [National Park], that should get people’s attention,” U. engineering student Alexis Richards said. It costs $30 to drive into Zion, but nothing to drive into the Cottonwoods, where toilets and parking are in short supply.

Currently, cars driving up the canyon carry 1.8 people on average, 30 percent are occupied by a single person, and only 4 percent ride the bus. Two UTA parking lots serving canyon buses are barely used. Clearly there is room for getting more people in the canyon without increasing the number of vehicles. The challenge is getting people to leave their cars in the valley, Whitaker said.

The student team, supervised by U. engineering professors David Eckhoff and Steve Bartlett, conducted its study at the request of Salt Lake County’s Granite Community Council, whose neighborhoods at the canyon mouth are often choked with cars on busy ski-season days.

The same professors oversaw a similar study last year for Big Cottonwood, where students also proposed tolls. Such fees are controversial because many feel their taxes should cover the cost of roads and no one should have to pay to visit public land.

The Little Cottonwood study coincides with an major planning effort by the Utah Department of Transportation (UDOT), the U.S. Forest Service and the Utah Transit Authority (UTA), which provides winter bus service.

UDOT recently initiated an environmental impact statement for its planning effort and the public has until May 4 to submit “scoping” comments. The U. team’s final report will be issued in front of that comment deadline.

“We think better parking, better information, increased transit and increased occupancy in private vehicles would go a long way, along with safety components to take care some of the issues we see up the canyon,” UDOT planner Brandon Weston said at a recent meeting regarding the plan. “We have 27 planning studies that we can build on. We don’t want to redo anything that has already been done.”

Indeed, Little Cottonwood’s heavy traffic has been studied for at least 15 years and “planning fatigue” has already set in for some officials, while only incremental steps have so far been undertaken, such as Snowbird’s use of 21 vans to ferry employees to and from work and a summer shuttle between Alta and Albion Basin at the head of the canyon.

UDOT’s $4 million study should be complete by March 2020.

“We have studied the traffic from every which way we can,” Weston said. “We haven’t done anything with it yet. This project has some money to solve some of the issues we have been talking about for years.”

In response to Little Cottonwood’s congestion, lawmakers authorized $65 million for road upgrades, as well as the use of tolls anywhere in the state, but especially on State Route 210.

The U. team also endorsed tolls, both as a way to pay for upgrades and to create incentives for visitors to take transit and share rides, but members declined to identify prices. They did say tolls should be graduated so they are more expensive on crowded days — say weekends and holidays right after a storm has blanketed Alta and Snowbird with a bounty of powder — and less expensive for vehicles with multiple occupants.

Whitaker did say someone driving a single-occupancy vehicle into the canyon on a peak day should expect to pay more than $12.50 for that privilege. Revenues raised would be used for road maintenance, but also improvements at trailheads that could include parking and flushable toilets.

Ski area employees and Alta town residents would not be subject to the toll.

Two ideas the U. team did not study were adding additional travel lanes to the two-lane State Route 210 up the canyon and installing a 7-mile gondola to Snowbird. Either would be very expensive and have large impacts, according to team member Savanah Whitaker.

A gondola could move 5,500 people an hour, Whitaker said, but parking and passenger loading at the canyon mouth would pose logistical challenges that undermine the utility of such an approach.