 MORE IN Highway Geometric Design
VTU Civil Engineering (Semester 7)
Highway Geometric Design
May 2016
Total marks: --
Total time: --
INSTRUCTIONS
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary

1(a) What is PUC? What are factors affecting PCU values?
8 M
1(b) The following data were obtained from the spot speed studies carries out at stretch of highway during a certain period of time. Suggest
i) Speed limit for regulation of traffic.
ii) Lower speed group causing congestion.
iii) Speed for design of geometric elements.
 Speed range Kmph No. of  vehicles Speed observed Speed Range kmph No. of Vehivles observed 0 to 10 12 50 to 60 225 10 to 20 18 60 to 70 119 20 to 30 68 70 to 80 43 30 to 40 29 80 to 90 33 40 to 50 204 90 to 100 09
12 M

2(a) List the payment surface characteristics and explain briefly.
10 M
2(b) Write a note and mention IRC standards:
i) Width of formation   ii) Right of way-IRC only for open areas.
10 M

3(a) Derive an expression for overtaking sight distance.
8 M
3(b) Find the minimum sight distance to avoid head-on collision of 2-cars approaching at 90 kmph and 60 kmph. Given : t = 2.5 secs, f = 0.7 and Brake efficiency of 50% in either case.
6 M
3(c) The speed of overtaking and overtaken vehicles are at 70 kmph and 40 kmph respectively. Determine overtaking sight distance. Take = 0.99 m/sec2.
6 M

4(a) Write a design procedure of evaluating super elevation as per IRC.
6 M
4(b) A state highway passing through a rolling terrain has a horizontal curve of radius equal to ruling minium radius. Design all the geometric features of the curves.
Assume : V = 80 kmph, No. Of lane = 2 and I = 6 m.
14 M

5(a) Define Gradient and its types.
6 M
5(b) A vertical summit curve is formed at the intersection of two gradients, +3.0 and -5.0 percent. Design the length of summit curve to provide a stopping sight distance for a design speed of 80 kmph. Assume data as per IRC.
6 M
5(c) A valley curve is formed by a descending grade of 1 in 25 meeting an ascending grade of 1 in 30. Design the length of valley curve to fulfill both comfort and head light sight distance requirements for a design speed of 80 kmph. Assume allowable rate of change of centrifugal acceleration C = 0.6 m/sec3.
8 M

6(a) Define unchannelised and channelized intersections. Write a neat sketch, of typical unchannelised and channelized intersections.
10 M
6(b) What is intersection at grade? Explain the basic requirements of intersection at grade.
10 M