A massive and expensive network of new roads is emerging along a portion of Interstate 26 in North Charleston.

North Charleston roads

Project Completed Cost Who paid for it?

Palmetto Commerce Parkway 2011 $36.5 million Charleston County half-cent sales tax

Northside Drive proposed $42 million Charleston County half-cent sales tax

*Patriot Boulevard 2007-2008 $6.2 million Dorchester County Sales Tax Authority

*portions competed more than a decade ago not included

The proposed three-project bundle: I-26 interchange and Future Drive, South Aviation Avenue extension, International Boulevard relocation

A cost estimate for completing the projects has not been determined. Charleston County approved $80 million for design, engineering and acquiring the required right-of-way. The money will come fees that Boeing pays in lieu of paying taxes. A funding source for project construction hasn’t been determined, but North Charleston Mayor Keith Summey said the money likely will be the S.C. Transportation Infrastructure Bank.

Charleston and Dorchester counties, city of North Charleston

Dubbed the “Boeing Corridor,” the area is bounded by Dorchester Road and I-26, and by West Montague Avenue and Ladson Road. The area for many years has needed more roads to handle traffic, said North Charleston Mayor Keith Summey, but Boeing accelerated the need when it set up operations at Charleston International Airport.

The Palmetto Commerce Parkway, completed in 2011, launched the area improvements by providing access to 1,500 to 2,000 acres for commercial and industrial development, he said.

And three new projects — a new I-26 interchange, the extension of South Aviation Avenue and the relocation of International Boulevard — will complete the transition.

Charleston County Council recently approved $80 million for preliminary work to get those projects off the ground, Summey said. He thinks the money to complete them likely will come from the S.C. Transportation Infrastructure Bank, a state agency that funds large construction projects such as the Arthur Ravenel Jr. Bridge and the completion of Interstate 526.

Jim Armstrong, Charleston County’s assistant administrator, said, “There are a lot of unknowns” around the completion of those projects. “But we will go above and beyond with public input.”

Post and Courier reporters David Slade and Warren Wise contributed to this report.