Mark Clark Extension

Resources

• Mark Clark Extension Website
• Mark Clark Extension Map
• Segmenting into Two Phases
• Intergovernmental Agreement for the Mark Clark Extension (Jan 10, 2019)
• SCDOT Letter, April 2022
• SCDOT Letter, Dec 2022

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."

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 2022.  They have estimated that Phase 1 would cost about twice as much as Phase 2.
• Schedule:  Start in 2028 and finish in 2035
  • 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