Mark Clark Expressway - I-526

Welcome to the Mark Clark Expressway website!

Mark Clark Public Hearings

For information regarding the public hearings, including the displays and handouts that were available to the public, please click here.

Thank you for your interest in the proposed Mark Clark Expressway project.

The proposed project has been under careful consideration since the publication of the DEIS and the public hearings. Most recently, by Charleston County action per a resolution dated December 13, 2012, efforts associated with evaluation of the proposed Mark Clark Expressway are moving forward again. Charleston County has specifically approved advancing Alternative G through the Final EIS and Record of Decision, with the following modifications:

  • A grade-separated interchange at Folly Road, including an overpass at Up on the Hill Road on James Island
  • An overpass to maintain the connectivity of East Shore Lane in West Ashley
  • A speed limit of 45 miles per hour

In addition to these design modifications, Charleston County has requested that efforts be made to eliminate traffic signals along the route and provide an overpass at Riley Road on James Island.

Detailed evaluations of traffic impacts, potential environmental impacts, engineering analyses, and the modifications listed above will be evaluated through the development of the Final EIS. It is anticipated that the Final EIS will be complete and a Record of Decision will be made by the Federal Highway Administration in approximately 12 to 18 months.

Project Updates

Project Status Report (Summer 2011) ... find out more


The DEIS has been signed ... find out more


DEIS Documents ... find out more


The official public comment period ended on Sept. 30, 2010, click here for a summary of comments.
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