PORTLAND, Ore. >> Traffic is already a headache in central Oregon as thousands of people arrive before Monday’s total solar eclipse.

Traffic was backed up early today on U.S. Highway 26 near of Prineville, the last town before the turnoff for an eclipse-themed festival that’s expected to attract 30,000 people in a remote area with narrow, one-lane roads. A handful of gas stations in Bend and Prineville also ran out of fuel Wednesday before getting restocked.

The scene echoed one on Wednesday night, when eclipse traffic first began to swell. Traffic backed up for 12 miles on the same stretch of road, doubling the drive time between the towns of Redmond and Prineville as an estimated 8,000 cars passed through.

“The numbers of people who were coming in, we are beyond capacity really on that highway. Traffic is moving — it’s not stopped — but it’s taking a long time,” said Peter Murphy, a spokesman for the Oregon Department of Transportation in central Oregon.

Traffic officials were planning to reprogram traffic lights to provide more time on green lights on east-west routes. They are also working with festival officials to streamline the entry point to the event, Murphy said, and sketching out alternative routes to the festival turnoff.

In Madras, to the north, traffic was also picking up today but so far there were no traffic jams. Gas stations were still stocked, said Joe Krenowicz, executive director of the Jefferson County-Madras Chamber of Commerce.

The town of about 6,000 is considered one of the best viewing locations in the nation and is expecting at least 100,000 people over the next four days.

“We know that we will run out of gas at some times, but they will refuel. There will be some inconveniences,” he said.

“We’re encouraging people to come into Madras with a full tank of gas if they possibly can.”

Traffic elsewhere in the state was still normal, officials said, but more visitors were expected starting Thursday and into the weekend.

“When it comes, it will come as a rush,” said Dave Thompson, chief ODOT spokesman.

About 200,000 people are expected to visit Central Oregon in the coming days to see the rare celestial event. It’s the first total, coast-to-coast solar eclipse in the U.S. in 99 years and totality — when the moon’s shadow blocks the sun and casts a shadow on Earth — first makes landfall in Oregon, making the state a top destination for eclipse watchers.

State officials are urging travelers to log onto www.TripCheck.com before they leave or call 211, an information number about the eclipse set up for the public.