Width of formation or Roadway , Right of way and land width, Typical cross sections of road

1. DEPARTMENT OF
CIVIL ENGINERRING
Width of Formation or Roadway
Right of Way and Land Width
Typical Cross Sections of Roads
Er. Ramprasad Kumawat
M.Tech

2. Width of Formation or Roadway
• Width of formation or roadway is the sum of
widths of pavement or carriageway including
separators, if any and the shoulders.
• Formation or roadway width is the top width
of the highway embankment or the bottom
width of highway cutting excluding the side
drains. Refer in Fig.

4. The width of roadway standardized by the
Indian Road Congress is given table 4.3

5. • Notes: (a) In multilane highways, roadway
width should be adequate for the requisite
number of traffic lanes besides shoulders and
central median.
• (b) The minimum roadway width on single
lane bridge is 4.25 m.

6. Right of Way and Land Width
• Right of way is the area of land acquired for
the road, along its alignment. The width of the
acquired land for right of way is known as
'land width' and it depends on the importance
of the road and possible future development.
• A minimum land width has been prescribed for
each category of road.
• A desirable range of land width has also been
suggested for each category of road.

7. • While acquiring land for a highway it is desirable
to acquire more width of land as the cost of
adjoining land invariably increases very much,
soon after the new highway is constructed.
• Also road side developments start taking place
making it difficult later on to acquire more land
required for future widening or for other
improvements.
• In some cases the lower width within the
suggested range may have to be adopted in view
of high cost of land and other existing features.
• This is particularly true in urban and industrial
areas

8. The land width is governed by the
following factors:
(a) Width of formation which depends on the
category of highway, width of roadway and
road margins
• (b) Height of embankment or depth of cutting
which is governed by the topography and the
vertical alignment
• (c) Side slopes of embankment or cutting
which depend on the height of the slope, soil
type and several other considerations including
aesthetics

9. • (d) Drainage systems and their size, which
depends on the rainfall, topography, and run
off
• (e) Sight distance considerations on horizontal
curves, as there is restriction to the visibility
on the inner side of the curve due to
obstruction such as building structures etc. At
sharp curves it is desirable to acquire a wider
strip of land, particularly on the inner side of
the horizontal curve in order to avoid
obstructions to visibility. Refer Fig 4.5

11. • (f) Reserve land for future widening is to be
planned in advance based on anticipated future
development and increase in the traffic.
• The values of normal and range of land width
standardized by the IRC for various categories
of roads in rural areas and in different terrains
are given in table 4.4

13. • It is desirable to control the building
construction activities on either side of the
road boundary, beyond the land width acquired
for the road in order to reserve sufficient space
for future improvement of roads.
• Therefore, it is necessary to prohibit the
building activities up to 'building line' with
sufficient setback from the road boundary.
• In addition it is desirable to exercise control of
the nature of building up to further set back
distance up to the 'control lines'.

14. • The overall width requirements between the
building lines and the control lines on either
side of the road, recommended by the IRC for
different road classifications and different
terrain conditions in rural areas are given in
Table 4.5.

16. • It may be seen from Tables 4.4 and 4.5 that the
normal land width required for the National
and State Highways on open plain terrain is 45
m and the maximum land width required is 60
m,
• the corresponding width between the building
lines is 80 m and that between the control lines
is 150 rn, thus allowing set back distances of
10 and 45 m beyond the road boundary lines
with the maximum recommended road width.

17. • *Split levels
• The recommended land widths for different
classes of urban roads are, 50 to 60 m for
arterial roads (high types of urban roads meant
for through traffic, with controlled access), 30
to 40 m for sub-arterial roads, 20 to 30 m for
collector streets (urban roads and streets meant
for collecting traffic from local streets and feed
to the arterial and sub-arterial roads) and 10 to
20 m for local streets.

18. Typical Cross Sections of Roads
• Some of the typical cross sections of different
categories of highways in rural areas and a
typical urban arterial road are shown in Fig.
4.6 to 4.10.

24. • THANKS!
• Gmail :
ramkumawat001@gmail.com