Ironman triathlon is coming to Morro Bay for the first time. How will it affect traffic?

Some lanes on four-lane stretches of Highway 1 between Morro Bay and San Simeon, and some prime Morro Bay roads and highway on- and off-ramps, will be closed Saturday for up to 14 hours for the Ironman 70.3 triathlon event.

The Ironman triathlon, the city ‘s first, is described on the event website as “a protected swim in Morro Bay, rolling hills on the bike through vineyards to ocean views and a finish line along the Embarcadero.”

The race features a 1.2-mile swim, a 56-mile bike race and a 13.1 mile run in succession.

According to Caltrans, nearly 2,000 Ironman participants will use Highway 1 from Morro Bay to San Simeon between 6 a.m. and 1 p.m. Saturday.

“Cyclists will ride within a closure which includes the right lane of Highway 1 and shoulder for the first 7 miles before using only the shoulder,” the second release said.

“Bicyclists will travel along northbound Highway 1 from Atascadero Road/Morro Road to Hearst Castle Road and back, primarily using the shoulder,” Caltrans wrote in a news release.

The right lanes in both directions of Highway 1 will be closed from Highway 41 to San Geranimo Road, the release said. Traffic will be restricted on Atascadero Road to Main Street.

Also, riders will travel in a single file on Highway 1 at Toro Creek Bridge in Morro Bay and Old Creek Bridge in Cayucos where construction is underway.”

In Morro Bay, some on- and off-ramps at Highway 41 will be closed from 6 a.m. to 1 p.m., the state roads agency said, as will the southbound on- and off-ramps at Cayucos Creek Road.

Traffic signals will go to flashing red along the highway at San Jacinto, Yerba Buena and Main streets in Morro Bay, and at the Windsor Boulevard, Burton Drive and Cambria Drive intersections in Cambria.

The California Highway Patrol and the Morro Bay Police Department will help with traffic control, according to Caltrans.

Morro Bay roads, parking lots closed for Ironman event

All or part of some major streets in Morro Bay will close at 3 a.m., Saturday, with most reopening at 5 p.m.

Affected roads include Embarcadero and Front, Harbor, Pacific, Olive and Main streets, plus Morro Avenue, Bayshore Drive and the north side of Atascadero Road.

Other roads likely to be impacted will be route turns and end points at Coleman Drive, Market Avenue and Park View Drive, as well as Morro Bay State Park campgrounds.

There will be no-parking zones in some harbor and oceanfront parking lots and areas through Saturday, Sunday or May 22, depending on the location. Some of the restrictions will start Monday, Thursday and Friday.

Those include the parking lots at Maritime Museum, 714 Embarcadero and Coleman Park, plus Front Street from Harbor Street to Embarcadero, Coleman Drive from the Morro Rock parking lot and a portion of the Rock parking lot. The Maritime Museum lot closure began May 12.

For more information about traffic impacts, go to tinyurl.com/3p9yhz6v.

For race and event details, go to ironman.com/im703-morro-bay.