The No Turn on Red Signal sign indicates to drivers that during the red traffic signal indication they are not permitted to turn left or right as indicated per version of the sign. Such prohibitions may be required for any of the following conditions:

1. Inadequate sight distance or restrictive geometrics;
2. Irregular intersection with more than four approaches and multi-phase control;
3. Conflicts with an exclusive pedestrian phase;
4. The existence of unusual movements such as double left turns;
5. A history of left turn on red collisions on a particular approach; or
6. The proximity of a railroad crossing with signal pre-emption on that approach.

The sign should be mounted on the far right (or the far left) corner of the intersection. In many cases it is installed adjacent to the far right (or the
far left) signal head. When a near right (or left) signal head exists, another sign should be installed. Other special circumstances such as a wide intersection may require the installation of additional signs.