WASHINGTON – Federal regulators have approved the construction of a 28-mile rail line that will serve Volvo’s new assembly plant near Charleston, S.C.

The Surface Transportation Board, in a decision issued on Monday, gave the green light to Palmetto Railways’ proposal to build the so-called Camp Hall rail line.

It will run 28 miles from the Camp Hall Commerce Park in Ridgeville, site of the assembly plant Volvo opened in 2018, to the CSX Transportation Cross Subdivision adjacent to the Santee Cooper Cross Generating Station.

The state-owned Palmetto Railways is the terminal switching line for the South Carolina Ports Authority rail-served marine terminals at the Port of Charleston. It will build, own, and operate the new line.

It’s not yet clear when construction will begin.

“Following receipt of this approval, Palmetto Railways will continue other pre-construction activities associated with the project, including permitting related to state and local regulatory requirements, full design of the line, and right-of-way acquisition,” says Alex Camp, a spokeswoman for the South Carolina commerce department.

It’s expected to take 18 to 24 months to build the line, Camp says.

South Carolina pledged to fund the industrial line as part of the $200 million in incentives for Volvo to locate its first American assembly plant in the state.

The $1.1 billion Volvo plant produces the S60 midsize sedan, which is exported around the world through the Port of Charleston, and in 2022 will begin building the XC90 sport utility vehicle. It has the capacity to build 150,000 vehicles a year.

— Updated at 1:15 p.m. CDT with comment from South Carolina commerce department, additional details.