CHARLESTON, S.C. (AP) — South Carolina’s road agency says the cost to complete an Interstate 526 loop has tripled.

The state Department of Transportation says the Mark Clark Extension going from West Ashley through Johns Island and to James Island will cost more than $2.3 billion.

That’s because of rapidly rising costs of buying land and construction. The state’s share of the new highway is capped at $420 million in a 2019 agreement.

That means Charleston County would need to find nearly $2 billion to complete the project — or six times more than it planned. The Coastal Conservation League opposes the project.