Problems and maintenance of hilly roads require special consideration due to steep slopes and terrain. Key challenges include landslides caused by heavy rainfall and loose soil, effective drainage to prevent soil erosion from high water speeds, avoiding tight hairpin bends and maintaining sufficient sight distances, and snow clearance in winter conditions. Solutions involve good drainage systems, retaining walls, controlled road alignment and gradient, and use of salt or special equipment for snow removal.

1. Problems and Maintenance In
Hilly Roads
Presented By:-
Abhishek Bharti

2. Hill Road
• Hill road is defined as the one which
passes through a terrain with a cross
slope of 25% or more.
• IRC-SP-48-1998 Hill Road Manual
• IRC 52-2001 About the Alignment
Survey and Geometric Design of Hill
Roads

3. Special Consideration For Hilly Roads
• Alignment of Road
• Most of the length should be in ruling gradient
• Deep Cutting is avoided
• Tunnels should be avoided
• Grid based Technology should be adopted for
4 lane highways

4. Grid Based Technology
• Reduce Landslides
• Increase in Cost
• Require more area

5. Problems in Hilly Roads
• Landslide
• Drainage
• Soil Erosion
• Ineffective Rise and Fall
• Hair Pin Bends
• Sight distance
• Snow Clearance

6. Landslide
• Due to heavy rainfall
• Loose soil
• Deforestation

7. Measures to protect roads from landslides
• Good surface drainage, proper side and cross
drainage
• Construction of Retaining Wall and breast wall
• Growth of vegetation
• Stability of slopes should be check, roads should be
pass from stable soil or rock.

8. Drainage
• Due to steep slope in hilly the speed of water is high
which leads to soil erosion
• Also effect the pavement properties.
Types
Surface
Drainage
Sub Surface
Drainage

9. Surface Drainage
Collection of Surface water through
• Side Drains
• Cross Drains

10. Subsurface Drainage
• Lowering the Water table
• Control Seepage Flow
• Capillary cut off

11. Soil Erosion
• Due to high flow of water there is more soil
erosion
• We can reduce by constructing Retaining wall
And breast walls

12. Ineffective Rise and Fall
• While designing the road in hilly area there
are ineffective rise and falls so the alignment
of the road should attains the ruling gradient
in maximum length.
• Ruling gradient is the maximum design
gradient
• Exceptional gradient should not exceeds for
100m length.

13. Hair Pin Bend
The bend on the road with very acute inner
angle making necessary to turn vehicle about
180 degree.
• Avoided as far as possible
• Minimum distance between two hair pin bend
is 60m
• Minimum radius of inner curve is 14m
• Maximum gradient is 2.5%
• Minimum Design speed is 20Km/hr

14. Hair Pin Bend

15. Sight Distance
• Visibility is an important requirement for safety on roads.
• It is necessary that sight distance of sufficient length is available to
permit drivers enough time and distance to stop their vehicles to
avoid accidents.
• It is sufficient in valley curve but problem occur in horizontal and
summit curve

16. Snow Clearance
• Hilly roads are covered with snow in winter season
it not only reduce the speed but also block the road
• Difficult to drive and increase in accident rate.

17. Snow Clearance Method
• Snow can be removed manually or by special equipment like dozers, snow masters
• By Salt Application commonly used NaCl, CaCl2
• Approx. 90-180 Kg of salt is needed per Km for two lane road.