The crush of traffic begins around noon.

Tens of thousands of cars steer toward Interstate 5, motorists in the Salem area immediately ready to hit the road after witnessing a solar eclipse beginning to end from inside the path of totality.

The freeway grinds to a halt. Onramps backup. Main roads become parking lots.

Crashes ensue. Someone gets injured. Emergency responders have trouble getting by.

It stays like this for hours.

In a world of worst-case scenarios, this is but one illustration of the type of trouble that could play out in Oregon as a historic eclipse traverses the nation Aug. 21.

Public officials hope the extraordinary event passes with minimal problems. But it's their job to consider all the things that could go wrong. That list includes major wildfires, fuel or food shortages, fights or civil unrest, even a disease outbreak.

With less than one week remaining, state officials say they're as ready as possible for an unprecedented event that is projected to increase Oregon's population by 25 percent, drawing an estimated 1 million visitors. State officials and Gov. Kate Brown's office will discuss preparations during a press conference Tuesday morning in Salem.

Officials say their eclipse planning is invaluable, even if the biggest headache turns out to be traffic jams.

"If there's ever an emergency or disaster, we'll be better prepared because of this," said Cory Grogan, a spokesman for Oregon's Office of Emergency Management.

The state's emergency management agency has been planning for the eclipse for about a year, coordinating with more than 50 federal, state, local and tribal agencies, Grogan said. Part of their work included assessing potential dangers facing Oregonians and visitors.

Officials compiled a 12-page risk assessment for the eclipse, which The Oregonian/OregonLive obtained through a public records request. The bare-bones review of various problems that could arise "is not based on any known risks at this time," the document says. Local jurisdictions are responsible for developing their own hazard assessments.

Here's a look at two of the biggest concerns: Traffic and wildfires.

TRAFFIC



State officials say 1 million out-of-state visitors could equal 250,000 additional vehicles, setting the stage for gridlock of epic proportions.

If 50,000 of those vehicles are in the Salem area and all attempt to leave immediately after the eclipse, for instance, highways would become impassable.

In fact, if half those vehicles headed north toward Portland, the bumper-to-bumper backup on I-5 would extend 23 miles across all three lanes, said Dave Thompson, a spokesman for the Oregon Department of Transportation.

"The system doesn't have the capacity to handle that," he said. "It just wouldn't work."

That's why transportation officials are urging motorists to consider the eclipse a three-day event, not a three-hour outing, hoping to disperse high volumes of traffic over an extended period.

State officials haven't offered any estimates about how long commutes will take, saying that unknown traffic and timing creates too many variables.

But in the state's risk assessment, congestion is listed as being "highly likely." That could lead to injury accidents and significant delays. The duration? "Hours to days," according to the state report.

Transportation officials are taking steps to help motorists get around.

Thompson said the state will place "lots and lots" of digital reader boards along highways to provide traffic updates and information. And extra maintenance and incident-response crews will be staged along highways, such as U.S. 26 and U.S. 97 in central Oregon, and I-5 and Intestate 84 in eastern Oregon.

"If something happens they can get there a lot quicker because they're closer," Thompson said.

State transportation officials also have implemented traffic plans limiting turns on highways in two cities, Madras and Lincoln City, where heavy congestion is expected. And the state recently updated its online traffic map, called TripCheck, to show traffic flow on many major highways throughout the state.

"Hopefully it could be at least partly useful," Thompson said. "It won't be very useful if everybody's stuck in a traffic jam."

Thompson said officials have "done everything we can conceivably do" to prepare for the eclipse. But he still expects some frustrated motorists to blame or question the state for not taking additional steps to ease travel. He said motorists need to make conscientious choices about driving during busy hours.

For officials, success won't simply be about gridlock.

"I fully expect to hear people say, 'I wish I hadn't been caught in that traffic jam,'" Thompson said. "I'm not sure how we'd try to define success. If people stay safe. If everyone survives. If we don't have any loss of human life in a backup."

WILDFIRES

Four wildfires are currently burning in or near the path of totality. Officials worry about the potential for more fires from lightning strikes or campers.

Fire crews are preparing for the likelihood of at least a few small fires tied to eclipse activities. Crews will be stationed north and south of key areas to improve access, said Bobbi Doan, a spokeswoman for the Oregon Department of Forestry.

"For us, if we do have a fire start, it's about putting it out as soon as we can," she said.

The state's risk assessment deemed the probability of a major wildfire or emergency evacuation at moderate to high, with probable locations including rural areas with campsites.

The worst-case scenario, officials said, is a man-made blaze that endangers lives and makes travel in or out of a confined, mountainous area difficult or impossible.

Already, some 3,400 state campsites have been rented in or near the path of totality, said Chris Havel, a spokesman with Oregon State Parks. Officials expect about 12,000 overnight campers, a number that could easily double Monday depending on how many people crowd into roughly 50 state parks along the path.

And that doesn't count campers on federal land. Travelers are advised to check online for any burn restrictions at their destination.

"We want to prevent any problems from flaring up," Havel said, no pun intended.

Travelers should be aware of three wildfires burning in the Cascade mountain range and one on the Warm Springs Reservation.

If all goes as planned, the Nena Springs fire on the reservation could be contained by Aug. 16. The Whychus fire, about 10 miles northeast of Sisters, also could be contained this week.

But two other blazes, the Whitewater, 15 miles east of Detroit, and the Milli, nine miles west of Sisters, have not been contained at all. Officials have closed part of the Mt. Jefferson Wilderness area because of the Whitewater fire, which registers nearly 6,600 acres.

Carol Connolly, a spokeswoman for the Northwest Interagency Coordination Center, declined to say if any of the fires should give eclipse-watchers pause.

Connolly's advice: "Know what the conditions are before you head out the door."

-- Brad Schmidt

503-294-7628

@_brad_schmidt