The South Carolina Department of Transportation says crews should have finished splitting the westbound lanes by early today from mile marker 83 to mile marker 77.
Anyone wanting to get off on Spears Creek Church Road or Clemson Road will need to get into the right lane. Motorists in the left lane will have to travel to the Interstate 77 interchange without exiting.
The split will help crews build new westbound lanes quicker.
I-20 is being expanded to six lanes. The DOT says the lane split and a similar split earlier this year in the eastbound lanes will cut construction time from three years to 20 months.