Pavement is a load-bearing & load-distributing component of a road. We need to consider all types of vehicles for the geometrical design, but only vehicles with significant heavy loads are considered for pavement design. These vehicles are generally commercial vehicles. As per IRC, vehicles having a gross load greater than 3 tons are called commercial vehicles.
Pavement Design- Highway Engineering (Chapter-4) Read More »
In traffic control devices & regulation, we detailed discussed about traffic sign & road marking but remain topics are discussed in other post.
Traffic Control Devices & Regulation – Traffic Sign & Road Marking Read More »
In traffic control devices & regulation, we detailed discussed about traffic signal but remain topics are discussed in other post.
Traffic Control Devices & Regulation – Traffic Signal Read More »
In traffic control devices & regulation, we detailed discussed about intersection but remain topics are discussed in other post.
Traffic Control Devices & Regulation – Intersection Read More »
In Traffic Studies and Analysis, a detailed discussion about Origin and Destination Study, Accident Study & Parking Study.
In Traffic Flow Characteristics & Capacity Study, we detailed discuss about Traffic Capacity Studies, Traffic Flow Characteristics Studies.
Traffic Studies and Analysis → Traffic Flow Characteristics & Capacity Study Read More »
Traffic studies or surveys are carried out to analyze the traffic characteristics. These studies help in deciding the geometric design feature and traffic control for safe and efficient traffic movements. The traffic surveys for collecting traffic data are also called traffic census. The various traffic studies generally carried out are: Traffic Volume Study, Traffic Speed Studies.
The basic objective of traffic engineering is to achieve free & rapid flow of traffic with least no of accidents. For this various studies are carried out. These studies are divided into- Traffic Characteristics, Traffic Studies and Analysis, Traffic Control Regulation.
Vertical Curve are provided at the intersections of different grades to smoothen the vertical profile. The vertical curve used in the highway are of two types: Summit Curve, Valley Curve.
Design of Vertical Alignment Generally Highway is aligned to follow the natural topography keeping in view the drainage and other design consideration. The vertical alignment of a highway affects: Acceleration & Deceleration Operational cost of vehicle Sight distance Vehicle speed The vertical alignment consist of two element: 1. Gradient 2. Vertical curve Gradient: It
Set Back Distance: It is clearance distance, required from the centre line of pavement/road to the obstruction in ode to maintain the adequate sight distance to the curve. The set back distance or clearance required from the centre line of horizontal curve depends upon. Required sight distance (SD) Radius of horizontal Curve (R) Length of
Transition Curves: When a vehicle traveling on a straight road enters into a horizontal curve instantaneously, it will ca discomfort to the driver. To avoid this, it is required to provide a transition curve. This may be provided either between a tangent and a circular curve or between two branches of a compound or reverse
Transition Curves & Length of Transition Curve 2.20 Read More »
ExtraWidening: Extra width provide to Road at horizontal curve is called extrawidening. It is provided for following purposes: To avoid off tracking due to rigidity of wheel base. To encounter psychological tendency of driver. To increase visibility at curve. To account lateral skidding. Off tracking: Path travelled by front axle and path travelled by rear
Method of Obtaining Superelevation: Introducing superelevation on a horizontal curve in the field is an important feature in construction. The full super-elevation is attained by the end of transition curve or at the beginning of the circular curve. The attainment of superelevation may be split up into two parts: Elimination of crown of the cambered
Method of Obtaining Superelevation & Radius of Horizontal Curve 2.18 Read More »
Design of Superelevation⇒ Design of superelevation is a complex problem for mixed traffic conditions because different vehicles are moving with different speed hence the required superelevation are also different. In this case IRC suggest to design the superelevation for 75% of the design speed considering coefficient of friction is 0. Step.1: The
Equilibrium Superelevation: Equilibrium superelevation is that superelevation at which pressure at the inner and outer tyre will be equal. if the coefficient of friction is neglected i.e. f =0 then, e= , V in km/h This means that if a road surface is super elevated by tan-1 then the friction force will not be
Equilibrium Superelevation & Superelevation As Per IRC 2.16 Read More »
Superelevation: The transverse inclination throughout the length of horizontal curve by raising outer edge counteract w.r.t. inner edge, in order to counteract the effect of centrifugal force is known as superelevation (or cant or banking). The superelevation ‘e’ is expressed as the ratio of height of outer edge w.r.t. the horizontal width, i.e Superelevation (e)=
Superelevation & Analysis for Expression of Superelevation 2.15 Read More »
Stability Analysis on Horizontal Curve without Superelevation: It is the curve in plane to provide change in the direction to Central line on the road. When a vehicle travel on a horizontal curve, the centrifugal force act horizontally outward through the center of gravity of the vehicle. The centrifugal force depends upon the speed of
Stability Analysis on Horizontal Curve without Superelevation 2.14 Read More »
Design of Horizontal Alignment: Various design element to be considered in the horizontal alignment are: Design speed Type and length of transition curve Width of pavement Super elevation Radius of circular curve Set back distance Design Speed: The design speed is main factor on which most of the geometric design element depends including horizontal elements.
Design of Horizontal Alignment & Design Speed 2.13 Read More »
Curve: Curves are provided in highways in order that the change of direction at the intersection of straight alignments either in horizontal or vertical plane, shall be gradual. The necessity of curves arises due to the following reasons: Topography of the country To provide access to a particular locality Restrictions imposed by property Preservation of
Curve, Type of Curves & Advantages of Curves 2.12 Read More »
