Find Headlight And Intermediate Sight Distance
Here, a mathematical problem is taken to determine the value of headlight sight distance and intermediate sight distance, when the value of the design speed is given.
Find headlight sight distance and intermediate sight distance for a design speed of 65 Km/h (Use f=0.36, t=2.5 sec)
Design speed = 65 Km/h = 18 m/sec
Stopping Sight Distance (SSD) =( vt + v2/2gf ) = 18⨯2.5+ 182/(2⨯9.81⨯0.36) = 91m.
Another way, when design speed is taken as 65 Km/h.
SSD = (0.278V.t + V²/254f) = 0.278⨯65⨯2.5 + 652/254⨯0.36 = 91m so,
- Headlight Sight Distance(HSD) = SSD = 91m
- Intermediate Sight Distance(ISD) = 2(SSD) =2⨯91=182m