Sight distance - geometric design of roads, Civil Engineering

Sight Distance:

Sight distance is the distance along a road at which a driver has a visibility of objects and can safely stop his vehicle or overtake another vehicle.

Stopping Sight Distance

The stopping sight distance is the distance over which the driver traveling at a speed can apply brakes and bring the vehicle to a stop. It is composed of two component:

(a) Distance (d1) travelled in the brief time interval between the sighting of an object on the road and his applying the brake, known as the perception and brake reaction time.

(b) Braking distance (d2).

If t is the perception and brake reaction time in seconds, and v is the speed in m/sec,

d1 = vt

= 0.278 Vt, if V = speed in Km/hr t is taken as 2.5 seconds. Thus,

d1 = 0.278 × V × 2.5

= 0.695 V

The braking distance d2 if given by :

v2 = 2. a. d2, where a = deceleration = f . g,

where f = coefficient of friction, which varies from 0.3 to 1.0

g = acceleration due to gravity = 9.81 m/sec2

∴          v2 = 2 × f × 9.81 × d2

∴          d2 =     v2/2 ×  f × 9.81= (V/3.6)2  (1/2 × f × 9.81 ) =V2/254 f

where V = speed in Km/hr.

Posted Date: 1/22/2013 2:39:21 AM | Location : United States

Related Discussions:- Sight distance - geometric design of roads, Assignment Help, Ask Question on Sight distance - geometric design of roads, Get Answer, Expert's Help, Sight distance - geometric design of roads Discussions

Write discussion on Sight distance - geometric design of roads
Your posts are moderated
Related Questions
what is the errors faced in leveling servey

Q. Constriction of waterway at bridges? Constriction of waterway at bridges is effected by extending the approach banks to cover spill area or, in addition, part of active chan

Maintenance of Terminal Building: All accessories such as lighting, water, sanitation, telephone and public address system should be maintained in a good condition. Disposal

This assignment is a Hydraulic Design assignment for Civil Engineering Major in USA. Please try if there is someone professional who can do this work because it''s too sensitive. f

For a solid circular shaft transmitting torque, the shape factor is

Explain Template Jig? 1) Template jig is the simplest type of jig, employed for accuracy than speed. 2) This jig fits over, on, or, into the work and is not generally clampe

Q. What are advantages and disadvantage of varnishing? Varnish is a clear pale solution of a resinous substance ( like amber, common resin, copal, lac, or shellac 0 dissolved i

describe setting out right angle at given point on a chain line and when the point lies outside the chain line