GATE Questions & Answers of Geometric design of Highways - Cross-Sectional elements, Sight distances, Horizontal and Vertical alignments

What is the Weightage of Geometric design of Highways - Cross-Sectional elements, Sight distances, Horizontal and Vertical alignments in GATE Exam?

Total 23 Questions have been asked from Geometric design of Highways - Cross-Sectional elements, Sight distances, Horizontal and Vertical alignments topic of Transportation Infrastructure subject in previous GATE papers. Average marks 1.78.

A super -elevation e is provided on a circuler horizontal curve such that a vehical can be sttoped on the curve without sliding Assuming a design v and maximum cofficient of side friction fmax, which one of the following critearea should be satisfied?

The radius of a  horizontal circular curve on a highway is 120 m. The design speed is 60 km/hour, and the design coefficient of  lateral friction between the tyre and the road surface is 0.15. The estimated value of superelevation required (if full friction is assumed to developed), and the value of coefficient of friction needed (if no superelevation is provided) will, respectively, be

While aligning a hill road with a ruling gradient of 6%, a horizontal curve of radius of 50 m is encountered. The grade compensation (in percentage, up to two decimal places) to be provided for this case would be ____________.

A two lane, one-way road with radius of 50 m is predominantly carrying lorries with wheelbase of 5 m. The speed of lorries is restricted to be between 60 kmph  and 80 kmph. The mechanical widening and psychological widening required at 60 kmph are designated as Wme,60 and Wps,60 , respectively. The mechanical widening and psychological widening required at 80 kmph are designated as Wme,80 and Wps,80 , respectively. The correct values of Wme ,60 , Wps ,60, Wme ,80 ,Wps ,80 , respectively are

A motorist traveling at 100 km/h on a highway needs to take the next exit, which has a speed limit of 50 km/h. The section of the roadway before the ramp entry has a downgrade of 3% and coefficient of friction ( f ) is 0.35. In order to enter the ramp at the maximum allowable speed limit, the braking distance (expressed in m) from the exit ramp is _________

On a circular curve, the rate of superelevation is e. While negotiating the curve a vehicle comes to a stop. It is seen that the stopped vehicle does not slide inwards (in the radial direction). The coefficient of side friction is f. Which of the following is true:

A sign is required to be put up asking drivers to slow down to 30 km/h before entering Zone Y (see figure). On this road, vehicles require 174 m to slow down to 30 km/( the distance of 174 m includes the distance travelled during the perception – reaction time of drivers). The sign can be read by 6/6 vision drivers from a distance of 48 m. The sign is placed at a distance of x m from the start of Zone Y so that even a 6/9 vision driver can slow down to 30 km/h before entering the zone. The minimum value of x is ________ m. The perception-reaction time for a vehicle travelling at 90 km/h, given the coefficient of longitudinal friction of 0.35 and the stopping sight distance of 170 m (assume g = 9.81 m/s2), is _____________ seconds.

A road is being designed for a speed of 110 km/hr on a horizontal curve with a super elevation of 8%. If the coefficient of side friction is 0.10, the minimum radius of the curve (in m) required for safe vehicular movement is

For two major roads with divided carriageway crossing at right angle,a full clover leaf interchange with four indirect ramps is provided. Following statements are made on turning movements of vehiclesto all directions from both roads. Identify the correct statement:

For a portion of national highway where a descending gradient of 1 in 25 meets with an ascending gradient of 1 in 20, a valley curve needs to be designed for a vehicle travelling at 90 kmphbased on the following conditions.

(i) headlight sight distance equalto the stopping sight distance (SSD) of a level terrain consideringlength of valley curve> SSD.
(ii) comfort condition with allowablerate of change of centrifugal acceleration = 0.5 m/sec3.

Assume total reaction time = 2.5 seconds; coefficient of longitudinal friction of the pavement= 0.35; height of head light of the vehicle =0.75 m; andbeam angle = 1°.

What is the length of valley curve (in m) based on the head light sight distance condition? __________

For a portion of national highway where a descending gradient of 1 in 25 meets with an ascending gradient of 1 in 20, a valley curve needs to be designed for a vehicle travelling at 90 kmphbased on the following conditions.

(i) headlight sight distance equalto the stopping sight distance (SSD) of a level terrain consideringlength of valley curve> SSD.
(ii) comfort condition with allowablerate of change of centrifugal acceleration = 0.5 m/sec3.

Assume total reaction time = 2.5 seconds; coefficient of longitudinal friction of the pavement= 0.35; height of head light of the vehicle =0.75 m; andbeam angle = 1°.

What is the length of valley curve (in m)based on the comfort condition? __________

The following data are related to a horizontal curved portion of a two-lane highway: length of curve = 200 m, radius of curve = 300 m and width of pavement = 7.5 m. In order to provide a stopping sight distance (SSD) of 80 m, the set back distance (in m) required from the centre line of the inner lane of the pavement is

If v is the initial speed of a vehicle, g is the gravitational acceleration, G is the upward longitudinal slope of the road and fr is the coefficient of rolling friction during braking the braking distance(measured horizontally) for the vehicle to stop is

Consider the following statements in the context of geometric design of roads.

I: A simple parabolic curve is an acceptable shape for summit curves

II: Comfort to passengers is an important consideration in the design of summit curves

The correct option evaluating the above statements and their relationship is

The design speed for a two-lane road is 80 kmph. When a design vehicle with a wheelbase of 6.6 m is negotiating a horizontal curve on that road, the off-tracking is measured as 0.096 m. The required widening of carriageway of the two-lane road on the curve is approximately

The value of lateral friction or side friction used in the design of horizontal curve as per India Roads Congress guidelines is

A crest vertical curve joins two gradients of +3% and -2% for a design speed of 80km/h and the corresponding stopping sight distance of 120m. The height of driver’s eye and the object above the road surface are 1.20m and 0.15m respectively. The curve length (which is less than stopping sight distance) to be provided is

A horizontal circular curve with a centre line radius of 200 m is provided on a 2-lane, 2-way SH section. The width of the 2-lane road of 7.0 m. Design speed for this section is 80 km per hour. The brake reaction time is 2.4 s, and the coefficients of friction in longitudinal and lateral directions are 0.355 and 0.15, respectively.

The safe stopping sight distance on the section is

A horizontal circular curve with a centre line radius of 200 m is provided on a 2-lane, 2-way SH section. The width of the 2-lane road of 7.0 m. Design speed for this section is 80 km per hour. The brake reaction time is 2.4 s, and the coefficients of friction in longitudinal and lateral directions are 0.355 and 0.15, respectively.

The set-back distance from the centre line of the inner lane is

The extra widening required for a two-lane national highway at a horizontal curve of 300 m radius, considering a wheel base of 8 m and a design speed of 100 kmph is