Geometric Design

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. Note: This topic is part of the second chapter of Highway Engineering. I suggest reading this topic in the context of the complete chapter: Geometric Design of Highway. If you want to read

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

ExtraWidening: Extra width provide to Road at horizontal curve is called extrawidening. Note: This topic is part of the second chapter of Highway Engineering. I suggest reading this topic in the context of the complete chapter: Geometric Design of Highway. If you want to read the entire Highway Engineering, click here: Highway Engineering. It is

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

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. Note: This topic is part of the second chapter of Highway Engineering. I suggest reading this topic in the context of the complete chapter: Geometric Design

Equilibrium Superelevation: Note: This topic is part of the second chapter of Highway Engineering. I suggest reading this topic in the context of the complete chapter: Geometric Design of Highway. If you want to read the entire Highway Engineering, click here: Highway Engineering. Equilibrium superelevation is that superelevation at which pressure at the inner and

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). Note: This topic is part of the second chapter of Highway Engineering. I suggest reading this topic in the context

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. Note: This topic is part of the second

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 Note: This topic is part of the second chapter of Highway Engineering. I suggest reading this topic in the context

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. Note: This topic is part of the second chapter of Highway Engineering. I suggest reading this topic in the context of the complete chapter: Geometric Design of

Intermediate sight distance (ISD): On a horizontal curve, the requirement of overtaking sight distance can not always be satisfied. In such cases overtaking is prohibited by using regulatory signs. To provide an opportunity for overtaking operation on horizontal curves or in restricted areas, we provide intermediate sight distance, i.e. equals to twice of stopping sight

Overtaking Sight Distance (OSD): Note: This topic is part of the second chapter of Highway Engineering. I suggest reading this topic in the context of the complete chapter: Geometric Design of Highway. If you want to read the entire Highway Engineering, click here: Highway Engineering. If all the vehicle ply on the road at the

Stopping Sight Distance (SSD): The minimum distance visible to a driver ahead to safety stop a vehicle travelling at design speed without collision with any other obstruction is termed as “SSD”. It is also termed as “Absolute Minimum Sight Distance” or ” Non-Passing Sight Passing”. Note: This topic is part of the second chapter of

Sight Distance: Sight distance is the length of road visual a head to the driver at any distance. ( it is considered by taking the height of eyes of the driver to be 1.2 m and height of object to be 0.15 m). Note: This topic is part of the second chapter of Highway Engineering.

Roadway / Width of Formation: It is the sum of with pavement or carriageway including separator (if any) and the shoulder. Roadways width is the top of highway embankment or bottom width of highway cutting excluding the side drain. Width of Formation of various class of Road are as follows: Note: This topic is part

Shoulder: Extra width provided adjacent to edge of pavement is called shoulder. It is provided for emergency point of view like Breakdown of vehicle, medical emergency etc. Note: This topic is part of the second chapter of Highway Engineering. I suggest reading this topic in the context of the complete chapter: Geometric Design of Highway.

Divider /Medians / Traffic separators Divider is an element provided to Road along the center line to separate two way traffic. The main function of median is to prevent “Head on collision” between vehicles moving in the opposite direction. it also serves following other functions: To channelize traffic into the streams. To protect the pedestrians.

Camber / Cross- Slope: Note: This topic is part of the second chapter of Highway Engineering. I suggest reading this topic in the context of the complete chapter: Geometric Design of Highway. If you want to read the entire Highway Engineering, click here: Highway Engineering. It is the slope provide to the road surface in