Highway-Sight Distance

Stopping Sight Distance (SSD) is the total distance travel by a vehicle from the instance driver aware on hazard till the brake is applied. However, SSD might not be sufficient when driver encounter difficult-perceived information / hazard. Therefore, Decision Sight Distance (DSD) is introduced which provides greater length for driver to detect the potential hazard, select appropriate action and maneuver safely. Passing Sight Distance (PSD) is only applied in two-lane two way whereby overtaking of slower vehicle by using lane used by opposing traffic.