Mark Clark Extension

Resources

Background

The Mark Clark Extension (MCE), also known as the 526 extension, has been in the planning stages for many years. During this time it has been a contentious issue on Johns Island.

Purpose and Need:

"The purpose of the Mark Clark Extension project is to increase the capacity of the regional transportation system, improve safety, and enhance mobility to and from the West Ashley, Johns Island, and James Island areas of Charleston."

Current Status:

The County must develop a plan to fund their portion of the project and the cost for litigation, bond servicing, and needed improvements to River and Brownswood Roads as well as contingencies for cost overruns. The Joint Bond Review Committee has yet to approve the State Infrastructure Bank to provide the $75M matching funds.

Highlights:

Scope: ~9.5 mi road from West Ashley to James Island with two connections on Johns Island
Lead organization: SCDOT
- Contact: Jae Mattox
Status:
- Latest cost estimate: $2.2B (was $2.35B), Dec 2022
- County will then determine funding sources by Spring 2023
Funding: $420M from State Transportation Infrastructure Bank, remainder from the County
Cost Estimate: $2.2B from SCDOT Secretary Christy Hall's letter from Dec 2, 2022. They have estimated that Phase 1 would cost about twice as much as Phase 2.
Schedule: Start in 2028 and finish in 2036
- Phase 1 (West Ashley to Johns Island): Start in 2028 and take 4 years to complete
- Phase 1 (Johns Island to James Island): Start in 2032 and take 4 years to complete