With the Eddie Aikau Big Wave Invitational at Waimea Bay set for Sunday, city officials are bracing for unprecedented traffic to the North Shore.

The contest — set to run for the first time since 2016, and a 10th time since launched in the mid-1980s — is expected to draw 30,000 to 40,000 spectators Sunday morning, officials said Friday at a news conference.

“Traffic will be difficult at best,” Honolulu Police Department Capt. Tate Nojima said.

In a bid to ease the congestion, the city is adding an early morning bus route, marked “52 Haleiwa- Waimea Bay,” which will run from Ala Moana Center to Waimea — at 4:30, 5, 5:30 and 6. The ride could take two hours as TheBus will stop at Kalihi Transit Center, Mililani Park and Ride, Wahiawa Armory and Wahiawa Park and Ride. Shuttles will also run from Haleiwa to Waimea.

Parking along Kamehameha Highway, from Ili­ohu Place to the Sts. Peter &Paul Mission, will be prohibited from 10 p.m. today until the event concludes.

Forecasters expect the swell to bring wave faces of 50 to 60 feet, met by an offshore wind.

“It’s been a long adventure,” said Clyde Aikau, Eddie’s younger brother and a co-director of the Eddie Aikau Foundation, at the news conference. The event almost ran earlier this month before unfavorable winds led the organizers to cancel it. This time the wind and the swell are expected to deliver ideal conditions for super-size waves. “It’s going right into Waimea Bay,” Clyde said.

This kind of swell might come once every five to six years, according to Ocean Safety Chief John Titchen. “It’s truly humbling to see one of our own honored,” Titchen said, recounting Aikau’s service as a lifeguard. “We tell Eddie stories today,” he said. In an age before Jet Skis, Titchen said, “He would just go.”

There will be parking at Waimea Bay, Clyde Aikau said. Parks and Recreation Director Laura Thielen said the department is setting up extra toilets and asked visitors to pack out any trash, and not to use drugs or alcohol, especially given the roiling ocean nearby.

Forty elite surfers — 34 men and six women — will compete in the one-day event, which Mayor Rick Blangiardi, a former linebacker, described as “the Super Bowl of surfing.”

Live coverage can be seen on KHII, KHON and Surfline.com. A Parks and Recreation news release advises, “We first encourage visitors to avoid the North Shore and instead enjoy the event’s live coverage,” given the number of spectators expected to attend.

Blangiardi said he will not know the cost of resources dedicated to the event until it concludes. “I’m really focused on the value of this more than the cost of it,” he said.

Clyde Aikau last surfed in the Eddie in 2016, in what he called his “farewell participation.” He’s excited to see new surfers participate in the event, like Maui residents Kai Lenny and Billy Kemper, and Portuguese surfer Nic von Rupp.

In addition to honoring the late Eddie Aikau, a big-wave champion surfer and lifeguard who rescued more than 500 people on Oahu’s North Shore, the event is being held in remembrance of Eddie and Clyde’s brother, Solomon Aikau III, 74, who died in October, and Roy “China” Uemura, 68, a Waikiki beachboy and surf contest organizer, who died earlier this month.

In Clyde’s last memory of Eddie surfing Waimea, his brother rode a red 12-foot gun with a pintail and no rocker, the upward curve on most boards that helps make steep drops. “He had the biggest smile on his face,” Clyde said.