I-526 Extension

Sign the petition to let Charleston County know that sales tax dollars should be used on sales tax projects, not the 526 extension!

Update: On June 3, 2019, the Coastal Conservation League and three Charleston County residents filed a lawsuit in South Carolina state court challenging the county’s use of funds from the 2016 half-cent sales tax for the Interstate 526 extension project. Andy Gowder of Charleston firm Austen Gowder is representing the environmental nonprofit and citizen plaintiffs.

The request for a declaratory judgement contends Charleston County is breaking its “contract with voters” by obligating half-cent sales tax money to the I-526 extension. In 2016, I-526 was not listed in the ordinance Charleston County Council approved to put the sales tax referendum on the ballot.

The voters were duped.

Plaintiffs are asking a judge to determine the validity of the Intergovernmental Agreement for I-526. Under that three-party contract, the S.C. Department of Transportation would build the road; the S.C. Transportation Infrastructure Bank would cover $420 million of the project cost; and Charleston County would cover the balance of at least $305 million. To cover its portion of the project contract, Charleston County has committed funds from the half-cent sales tax.

View the full legal complaint here

Despite our legal concerns, on Tuesday, June 4, 2019, the state Joint Bond Review Committee approved $12 million from the Transportation Infrastructure Bank and $12 million from Charleston County toward the I-526 project to be used for permitting work, as well as a cost estimate update from the Department of Transportation.


I-526 or the “Mark Clark Expressway” is an interstate in Charleston County that currently terminates at Savannah Highway in West Ashley and in Mount Pleasant. In June 2007, the State Infrastructure Bank (SIB) voted to fund the I-526 extension from the Savannah Highway terminus to the James Island Connector (SC-30).

This interstate road project to a rural sea island is a huge problem.

It doesn’t solve traffic congestion. The 8-mile extension is estimated to cost at least $725 million dollars (originally $420 million) and save drivers only 36 seconds in travel time from West Ashley to James Island. Further, it takes drivers from one flooded area to another, ending in the busy and flood-prone Hospital District on Calhoun Street.

It pulls money from other statewide priorities. $420 million dollars for I-526 is coming from the State Transportation Infrastructure Bank, the funding entity for all projects of statewide significance and economic development. Given their limited resources, by choosing to obligate funds to I-526, the state bank is deciding against funding improvements to the I-26 and I-85 corridors, freight rail, and new economic development like Boeing in North Charleston. The I-526 extension project is not ranked on the state priority list; it is ranked 15th on the regional priority list.

The proposed expansion of I-526 places pressure on rural areas and natural resources and is an inefficient use of valuable coastal land and habitat. Specifically, the proposed alignment (Alternative G) cuts through neighborhoods in West Ashley and the James Island County Park and impacts 17.4 acres of wetlands. Read the Draft Environmental Impact Statement here.

It promotes automobile-dependent transportation across Charleston County and increases sprawl outside the urban growth boundary rather than repairing intersections and roads near the problem’s source. This new contract calls for using half-cent sales tax funding, which was proposed to raise money to fix problem areas like Main and 17, Savannah Highway, Glenn McConnell Parkway. A large portion of the sales tax is supposed to fund the region’s first Bus Rapid Transit system to help commuters get out of traffic – and their cars.

There are better projects.  

Funding the half-cent sales tax projects in full would help relieve congestion in key areas. Sign our petition asking Charleston County to uphold their sales tax commitments here.

Rather than just saying “No” to this destructive project, the Coastal Conservation League hired a transportation planning firm to create a new alternative to this massive highway project. The alternative, “A New Way to Work,” would resolve traffic congestion in major bottleneck areas and cost less than half of the I-526 extension. When the SCDOT released their draft Environmental Impact Statement, however, the New Way to Work alternative was eliminated. We continue to work with the Southern Environmental Law Center to address why this alternative was not studied more closely.

Why do some people still think we need the I-526 extension?

Proponents claim that I-526 would improve hurricane evacuation for residents of Johns Island, James Island, and Wadmalaw Island – a flawed assertion on three counts. First, the official evacuation route from Johns Island and Wadmalaw Island is US 17 south to Walterboro, not via I-526. Further, spending this large sum of money on I-526 may come at the expense of projects that would actually improve evacuation off Johns Island, like a flyover bridge at Main Road and US 17. Second, building new roads into suburban areas encourages sprawl. If we extend I-526 onto Johns Island, we can expect subdivisions to take the place of farms and wetlands. Encouraging development on a vulnerable sea island is not a good way to improve our preparedness for a hurricane. Third, funneling more traffic onto I-526 from new development on James Island would worsen traffic at the intersection of I-526 and I-26, delaying evacuation from the coast.

In the comments on the Draft Environmental Impact Statement (EIS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Environmental Protection Agency (EPA) and others noted that the U.S. Corps of Engineers should not consider extending 526 to improve hurricane evacuation. The Corps agreed, responding: “Hurricane evacuation was not considered a need for this project.”

Where is the money for I-526?

Under the current three-party contract, the S.C. Department of Transportation would build the road; the S.C. Transportation Infrastructure Bank would cover no more than $420 million of the project cost; and Charleston County has agreed to cover the balance of at least $305 million.

In the newest Intergovernmental Agreement, Charleston County committed funds from the half-cent sales tax. After being approved at the Bank Board meeting, the contract moved to the state’s Joint Bond Review Committee, who then appointed a special subcommittee to determine the validity Charleston County’s commitment to use their sales tax funds. The subcommittee met on March 27, 2019 hearing presentations from the S.C. Transportation Infrastructure Bank chair, John B. White, Jr. and the S.C. Department of Transportation secretary, Christy Hall. During their testimonies both agencies stated that they believe that the new contract is better for South Carolina because it puts all financial risk on Charleston County to come up with the more than $300 million shortfall beyond the Infrastructure Bank’s $420 million commitment. Charleston County presented to the subcommittee on April 3, 2019, arguing the sales tax could be used on “anything that is defined as a road” and that the county was replete with cash.

But the new contract isn’t better for Charleston County. In fact, it is a lot worse. In the newest agreement, Charleston County is agreeing to pay at least $305 million, before paying for any unanticipated overruns. And Charleston County still cannot explain how they could fund the projects promised to the voters and I-526 with the sales tax revenue. Projects like the flyover at US17 and Main Road, Bus Rapid Transit along the I-26 corridor, CARTA funding, Savannah Highway Capacity Improvements, and redesigning Folly Road are all on the chopping block.

Voters who narrowly approved the 2016 sales tax believed at the time that they were taxing themselves to pay for badly needed projects that did not include I-526. At the time, Councilmembers publicly decried the suggestion that the sales tax would be used for I-526 and approved a list of half-cent sales tax projects that deliberately did not include the I-526 extension. In fact, on July 19 and 27, they specifically debated adding I-526 to the sales tax list and the vote failed. Charleston County published assurances that they would stick to the list. “As I have said many times, each needs to be considered separately. The half-penny sales tax program Charleston County Council passed this summer, which is on the November ballot, was the result of careful study of our road and transit needs and did not include funding for the Mark Clark… Worries that council will not complete these projects as proposed are unfounded.” – Op-Ed by Councilmember Sass, Oct. 29, 2016.

Local elected officials even held a press conference in support of the half-cent sales tax program. Standing behind a poster with a list of projects to be funded, these leaders assured Charleston County voters that our hard-earned tax dollars would be spent only on those listed county priorities.

Less than two months after voters agreed to the tax, Charleston County Council passed an ordinance committing $150 million for the I-526 extension without explaining where that money would be taken from.


The Coastal Conservation League continues advocate against the I-526 extension project and will periodically update this page as new information is provided.

Related Links

SCDOT Mark Clark Expressway Project Page

Recent News:

June 1, 2019: Editorial: Council should answer legal concerns about 526 funding

Excerpt: Charleston County officials have recently argued that 526 should qualify for half-cent sales tax funds because the referendum question voters approved in 2016 didn’t specifically list projects. But the ordinance did, and 526 was very conspicuously not among those listed. In fact, County Council voted in July 2016 to remove it from the ordinance.


Staff Contact

Jason Crowley · [email protected] · 843.723.7933

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