In which direction should mast arms face in relation to traffic?

Mast arms should face perpendicular to traffic because this orientation ensures maximum visibility for traffic signals. When traffic lights are mounted on mast arms that are positioned perpendicular to the road, drivers approaching the intersection can clearly see the signals, which helps in decision-making regarding stopping or proceeding. This design is crucial for enabling safe navigation through intersections by providing clear guidance to motorists.

Positioning the mast arms in this manner also aids in reducing confusion and enhances the effectiveness of the traffic control systems, promoting overall road safety. The other orientations would not provide the same level of visibility or would mislead drivers, potentially leading to unsafe driving conditions.