TEXAS – The Texas Department of Public Transportation is reminding drivers that the left lane on a divided highway is for passing only.

In a tweet, TxDOT said “We’ve heard many of you didn’t know.”

Drivers should only use the left lane to pass cars before moving back into the right lane, states TxDOT. The reasoning behind the lane restriction is to keep traffic flowing.

Driving in the left lane is punishable by a fine up to $200. Divided highways are defined as roads with a median strip separating traffic in both directions.