KIAWAH ISLAND — On an average summer weekend, a few blocks worth of cars waiting to get into Beachwalker Park cause this resort island apoplexy.

The traffic and parking gridlock for the PGA Championship this month threatens to keep the prestigious, lucrative golf event from returning.

So how do you fix it? How do you move and park thousands of cars, then shuttle tens of thousands of people per day across a narrow barrier island without long delays?

The answer might be relatively simple.

Kiawah Island Golf Resort interests plan to take care of their end — improving the parking and traffic morass that swamped the Freshfields Village traffic circle.

They, local leaders and at least one civil engineer say that, seven years from now, John’s Island growth might well take care of the other end — improving the choke-point roads on John’s Island.

Development at some level has been coming for years to John’s Island, and large tracts have been slated for development along the River Road farmland across the Kiawah River from the island.

The State Infrastructure Bank’s vote Friday to finance the entire $558 million to build the Interstate-526 extension across the island is widely seen as a nod to that pending development.

The extension is opposed by residents and groups wanting to limit the growth, but growth is expected to happen anyway.

“Traffic is going to continue to grow whether I-526 is built or not,” said William Davis, a civil engineering professor at The Citadel whose classes have studied John’s Island road issues.

“The earliest we could get a PGA Championship would be 2019. We wouldn’t be eligible for a U.S. Open until 2020. There are going to be a lot of changes to the area between now and then,” said Roger Warren, Kiawah Island Golf Resort president.

Traffic and parking gridlocks deviled the otherwise praised PGA Championship at Kiawah. PGA officials suggested that the mess would have to be fixed before the Ocean Course would be considered to host another championship.

The tournament has been estimated to have brought $90 million plus in revenue to the Lowcountry. It might have been even more valuable selling the area as a travel and residential destination.

Traffic backed up sometimes off John’s Island as tournament-goers piled onto the island’s narrow roads.

But the worst of it was at the end, Freshfields, where cars and shuttle buses converged on the Kiawah traffic circle, then into confined parking-area entrances along the two-lane road on and off Kiawah Island.

Only so much can be done to fix that mess.

The road is the only way on or off the island, and the secret to relieving large-event traffic congestion is to separate the people going in from the people going out, engineers say.

Moving parking far off-site to a location such as the parking areas around The Citadel or Citadel Mall isn’t feasible; those sites were looked at when planning for this year’s event, Warren said.

“There’s a huge cost factor. It could have tripled or quadrupled the (shuttle) cost. We didn’t think we could afford it,” he said.

The golf resort interests will look at other nearby sites to move parking, but the Freshfields area “is where our thinking is right now.”

Reach Bo Petersen at 937-5744, @bopete on Twitter or Bo Petersen Reporting on Facebook.