TxDOT’s policy requires LEFT LANE FOR PASSING ONLY (R4-2aT) signs to be installed along all highways with two or more lanes traveling in the same direction that have a posted speed of 75 miles per hour or higher. The sign should be installed after the speed limit sign using adequate sign spacing.

The LEFT LANE FOR PASSING ONLY sign is required to be installed on the right-hand side of the highway. On divided highways with adequate median width, it is strongly encouraged to install the LEFT LANE FOR PASSING ONLY sign on the left side of the highway as well as the right side.