Sight distance - geometric design of roads, Civil Engineering

Assignment Help:

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.


Related Discussions:- Sight distance - geometric design of roads

What is froude number - hydrolic system, What is Froude Number? Used to...

What is Froude Number? Used to determine if the flow is rapid, critical or tranquil.  Fr = 1 critical flow; Fr 1 supercritical flow In rectangular open channels:  Fr =

Project planning, can you please provide with an example for mobilisation a...

can you please provide with an example for mobilisation and demobilisation plan, induction and deployment schedule, broad execution schedule in excel,quantity schedule for major qu

WBM Road, if the WBM Road is constructed with 80mm , 40mm metal what will b...

if the WBM Road is constructed with 80mm , 40mm metal what will be the depreciation factor per year, how much thickness of the layer will be reduced per year due to trafic and rai

Explain about vierendeel girder, Q. Explain about Vierendeel girder? Vi...

Q. Explain about Vierendeel girder? Vierendeel girder design is sometimes adopted in design of footbridges. Traditionally truss design, triangular shape of truss is generally u

Grouting in segmental linings in tunnels, Q. Grouting in segmental linings ...

Q. Grouting in segmental linings in tunnels? Grouting is typically carried out under pressure in segmental linings at the time of tunnel construction due to the below reasons:

Planning of water transport facilities, Planning of Water Transport Facilit...

Planning of Water Transport Facilities: Definition of Terms In water transport system, a number of terms are used. It is necessary for a civil engineer to know the pr

Joints in concrete pavements, Joints in Concrete Pavements: Concrete ...

Joints in Concrete Pavements: Concrete pavements in India are of the jointed plain (unreinforced type). The following types of joints are needed in them : (a) Transverse C

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd