Horizontal and vertical separator lines are used to separate street names, designations, destinations, and lane assignment on certain types of signs. The separator lines should be fabricated from the identical sign border material as the parent sign, and should not be wider than the sign border width (typically 2 inches).

Partial horizontal lines are used to separate street names sharing an exit on an Interchange Sequence Series sign. The horizontal line should be placed in between the appropriate lines of copy. The vertical spacing between a line of copy and the horizontal line should be equal to the largest character (letter or numeral) in the line of copy (Figure 4‑50). The partial horizontal line should extend one-third of the sign width (including border) from both sides of the sign (Figure 4‑50).

Horizontal lines may also be used to separate a suburban or rural designation on a community interchanges identification sign (Figure 4‑51). For this case, the horizontal line should extend the entire width of the sign. The vertical spacing between a line of copy and the horizontal lines should be equal to the largest character (letter or numeral) in the line of copy.

Vertical separator lines are used to separate lane assignment on ramps downstream of multi-lane exits. They are used on single panel, overhead Advance Guide and Exit Direction signs to separate destinations, highways, or cardinal directions. The lateral spacing to the vertical line edge should be equal to the height of the largest letter used on the sign (Figure 4‑52). If the lane assignment shares the same destination information, the vertical line should extend from the top of the sign to the bottom edge of the last destination line of copy.