The slow-paced completion of Interstate 526 has hit two more stumbling blocks.

I-526 timeline

JUNE 2007: The state Department of Transportation agrees to manage the Mark Clark Expressway project on James and Johns islands.

AUGUST-SEPTEMBER 2010: At five public hearings held by the DOT, speakers are overwhelmingly opposed to Interstate 526 extension on the islands. At the hearings, the DOT presents its preferred route for the road and summarizes results of its environmental study.

APRIL 2011: Charleston County Council stands firm against completing I-526, despite a warning that the move would cost the cash-strapped county nearly $12 million. The S.C. Transportation Infrastructure Bank warns council members that the county would have to pay back what has been spent on the project so far for right-of-way issues and engineering and environmental studies.

JANUARY 2012: County Council reverses its vote and asks the state DOT to take over the project.

JUNE 2012: The Berkeley-Charleston-Dorchester Council of Government’s transportation committee votes to increase the estimate to complete I-526 from $489 million to $558 million.

SEPTEMBER 2012: DOT commissioners vote unanimously against taking over I-526 from Charleston County.

DECEMBER 2012: County Council votes 5-4 in favor of completing I-526. The resolution contains an amendment that the county will make a good faith effort to compensate people who live within 1,000 feet of the road for the drop in the value of their property. County staffers then begin work on drafting a revised three-party contract.

S.C. Department of Transportation commissioners are balking on signing off on the proposal to move forward with the $558 million project, amid concerns about who would be responsible for managing it and about compensating property owners who live within 1,000 feet of the road’s path.

The next step for the controversial extension of the Mark Clark Expressway across Johns and James islands involves updating the project’s three-party contract, known as an Intergovernmental Agreement.

In the project’s initial $420 million contract, Charleston County was the project’s sponsor, the DOT was responsible for building the road, and the S.C. Transportation Infrastructure Bank was responsible for paying for it. But Charleston County now wants more control of building the road, and the price has climbed substantially in recent years.

Commissioner Mike Wooten said he’s worried about the financial implications of an amendment in the county’s resolution to build the road.

The amendment, proposed by Councilwoman Anna Johnson, states that the county must make a good-faith effort to compensate property owners who live within 1,000 feet of the road for any drop in the value of their property. The hotly debated project passed with a 5-4 vote in December, with Johnson casting one of the deciding votes.

Wooten said he thinks the amendment could put the state on the hook for paying off Charleston County property owners. And he said the county’s amendment sets a dangerous precedent.

“Others will look to it and say, ‘You did it in Charleston, why not do it here?’ ” Wooten said. “If that’s the case, nobody could afford to build a new road again.”

He wants DOT lawyers to weigh in on the financial risks the amendment brings.

Members of the grassroots opposition group Nix 526 are pleased that the DOT is scrutinizing the project contract. The group recently has started holding information sessions in homes of those who live within 1,000 feet of the proposed road on how to complete claims for financial compensation, even though the county hasn’t invited anyone to file claims or set up a process to handle them.

Johns Island resident Rich Thomas, a member of Nix 526, said he attended a DOT workshop Thursday where commissioners received an update on the status of the project contract. He said the concerns that commissioners raised sounded a hopeful note for project opponents.

“We are on the cusp of killing this thing and burying it under its own weight of corruption and idiocy,” Thomas said. “We just need to keep hammering on it until it cannot be ignored any longer.”

Charleston County Council Chairman Teddie Pryor said he feels blind-sided by commissioners’ objections. County officials and the DOT project manager addressed all their concerns, he said, and he thought they were on board with the county’s plan.

Nix 526 members are out of line for demanding money, he said. “They’re not making claims,” he said. “They want a Christmas gift. Well, there aren’t going to be any Christmas gifts.”

Pryor said he was frustrated and ready to get going on the road. The county has the skill to build it, he said. The DOT allowed the county to take the lead on a major road project on Johnnie Dodds Boulevard, and the project turned out well.

He’s going to take the $420 million set aside for the project and get going on it, he said. “I’m going to start building. If I run out of money, I’ll just stop where I’m at.”

DOT Commissioner Jim Rozier said he supports the completion of I-526. But, he said, several commissioners are strongly opposed to the county’s proposed contract changes.

They are especially afraid of the financial compensation issue, he said. The issue shouldn’t be a problem for the DOT, he said, because any financial fallout would land on the county’s doorstep. But during Thursday’s meeting, he said, “I got nowhere saying it wasn’t a problem.”

The issue is going to pose a big problem for the county, he said. “It got brought up and it got traction,” he said. “I don’t know how Charleston is going to handle that.”

Rozier also said commissioners raised concerns about the county taking a larger role in building the road. He’s not worried about that either, he said, as long as the DOT has veto power over any county road-building decisions that aren’t up to DOT standards.

But he hopes the county understands the complexity of the task it is trying to take on, he said.

The DOT is responsible for all interstate and state highways in South Carolina, but not for city and county roads.

Rozier, a former Berkeley County supervisor, said in his former position, he wouldn’t have taken on such a large road project. “The scope of it is not for any county all on its own.”

Commission Chairman John Edwards said he can’t support the county having a role in managing the project. “Since we have to take it over when it’s done,” he said, “I think the DOT should manage the whole project.”

Edwards said the commission likely will vote on the contract in the next few months, possibly at a meeting in early December.

Reach Diane Knich at 937-5491 or on Twitter @dianeknich.