There are many types of sight distance. Here are a few:
Safe intersection sight distance (SISD): The distance required for a driver or rider on a major road to observe a vehicle entering from a side road, and to stop before colliding with it.
Stopping sight distance (SSD): The sight distance required by an average driver or rider, travelling at a given speed, to react and stop before striking an object on the road.
Approach sight distance (ASD): The distance required for a driver or rider to perceive marking or hazards on the road surface approaching an intersection and to stop.
Entering sight distance (ESD): The sight distance required for minor road drivers or riders to enter a major road via a left or right turn, such that traffic on the road is unimpeded.
Manoeuvre sight distance (MSD): The distance required for an alert driver or rider to perceive an object on the road and to take evasive action.
Minimum gap sight distance (MGSD): The minimum sight distance based on the gap necessary to perform a particular movement.
Overtaking sight distance (OSD): The sight distance required for a driver or rider to initiate and safely complete an overtaking manoeuvre.
Safe intersection sight distance (SISD): The distance required for a driver or rider on a major road to observe a vehicle entering from a side road, and to stop before colliding with it.
Stopping sight distance (SSD): The sight distance required by an average driver or rider, travelling at a given speed, to react and stop before striking an object on the road.
Approach sight distance (ASD): The distance required for a driver or rider to perceive marking or hazards on the road surface approaching an intersection and to stop.
Entering sight distance (ESD): The sight distance required for minor road drivers or riders to enter a major road via a left or right turn, such that traffic on the road is unimpeded.
Manoeuvre sight distance (MSD): The distance required for an alert driver or rider to perceive an object on the road and to take evasive action.
Minimum gap sight distance (MGSD): The minimum sight distance based on the gap necessary to perform a particular movement.
Overtaking sight distance (OSD): The sight distance required for a driver or rider to initiate and safely complete an overtaking manoeuvre.
(diagram source: Austroads)
