The Mark Clark Extension Project
This proposed highway extension project connects the Southern end of I-526/Hwy 17 with the James Island Connector and Downtown Charleston.
The following information was extracted from https://www.scdotmarkclark.com/
"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 the Charleston metropolitan area."
Current Project Schedule
Proposed 2-Phase Project
Here's a great video simulating the proposed extension from the air:
If you have questions, please visit https://www.scdotmarkclark.com/faq