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					ROAD ALIGNMENT AND GOOD
   SURVEY PRACTICES
The ideal alignment between two points
shall satisfy the following requirements
            1. Short
            2. Safe
            3. Economical
            4. Aesthetic
            5. Sound
            6. Environment
Factors controlling the alignment

   1. Obligatory points
   2. Geometric design
   3. Drainage
   4. Crossing (Drains, Railway lines, Roads
   5. Other considerations
   6. Special considerations for hill roads
   7. Special considerations for sand dune areas
The final location of the alignment is
based on ground verification


The engineering surveys are to be
carried out properly
The survey may be completed in the
following four stages


  1. Reconnaissance
  2. Preliminary survey
  3. Determination of final central line
  4. Final location and detailed survey
Detailed desk study to be carried out
before reconnaissance


   1. Topographical maps
   2. Geological and soil maps
   3. Arial photographs
 Existing topographical maps provide a
 very good source of information for the
 alignment design in
1. Identifying villages / towns connecting
2. Determining length of alternate routes
3. Identifying no. and location of cross drainage
   works and their catchments
4. Identifying location of crossing of railway lines /
   roads
After identifying various alternative alignments,
detailed field studies should be taken up for
each of the alternatives to select best routes
1. Site visit should be made to arrive relative utility
   of the alternatives in terms of providing
   connectivity to market centers, health, education,
   social, welfare and administrative centers
2. Problems of land acquisition, horizontal and
    vertical curves
3. Soil type, availability of construction materials,
    type and no. of crossings, etc,.
•An open traverse survey of the selected
route should be conducted with the help of a
theodalite, chain and tape


•The center line of the alignment should be
marked


•Longitudinal and cross section of the
alignment prepared in 80 m width taking
spot levels at 10m intervals
•Property lines on both sides and important
topographic details should be plotted on a
scale of 1 in 500
A badly aligned road is a source of


1. Potential traffic hazard
2. Increase in transportation cost
3. Stain to vehicle and road user
          ROAD LAND WIDTH


HIGHWAY       WIDTH OF ROAD LAND (MTS)


NH & SH                60 TO 100
MDR                    25 TO 30
ODR                    18 TO 25
RR / VR                12 TO 18
          ROAD LAND WIDTH


HIGHWAY       WIDTH OF ROAD LAND (MTS)


NH & SH                30 TO 40
MDR                    25 TO 30
ODR                    18 TO 25
RR / VR                12 TO 18
                                               CONTROL LINES


                               BOUNDARY LINE
               BUILDING LINE
CONTROL LINE




                                   ROAD



                                                           ROAD WAY




                                                           CRG WAY



                                                          ROAD LAND


                                                WIDTH BETWEEN BUILDING LINES

                                                WIDTH BETWEEN CONTROL LINES
                     CARRIAGE WAY




DRAIN                                       DRAIN


                ROAD IN EMBANKMENT


                     CARRIAGE WAY




        DRAIN                       DRAIN



                  ROAD IN CUTTING
ROAD CROSSINGS



WITH RAILWAY LINE


WITH WATER COURSE


WITH ANOTHER ROAD
ROAD CROSSINGS WITH
   RAIWAY LINE


 ROAD UNDER BRIDGE


 ROAD OVER BRIDGE
 ROAD CROSSINGS WITH
   WATER COURSE


COST OF THE CROSS DRAINAGE WORKS


COST OF ALTERNATE ALIGNMENT
ROAD CROSSINGS
 WITH OTHER
   ROADS
ROAD JUNCTION
                        Crossing Conflicts ……..16
                        Merging Conflicts ……… 8
                        Diverging Conflicts……. 8




CONFLICT POINTS AT AN INTERSECTION
AREA OF CONFLICTS AT AN INTERSECTION
AREA OF CONFLICTS WITH TREATMENT
TURNING MOVEMENTS WITH TREATMENT
                       Crossing Conflicts ……….0
                       Merging Conflicts ……… 4
                       Diverging Conflicts……. 4




MOVEMENTS AT ROTARY INTERSECTION
                        Crossing Conflicts …….…4
                        Merging Conflicts ……… 8
                        Diverging Conflicts……. 8




CONFLICT POINTS AT A SMALL CENTRAL
              ISLAND
MOVEMENTS AT A SMALL CENTRAL ISLAND
           WITH SIGNAL
MOVEMENTS AT UN-TREATED MEDIAN GAPS
MOVEMENTS AT TREATED MEDIAN GAPS
ROAD MARKINGS
4M




     3M
Inadequate Investigation


Results in large deviation in the project
estimate and time duration
 The execution agencies have to carry out
Physical feasibility
1.Engineering surveys
2.Geotechnical investigation
3.Hydrological investigations
4.Collection of traffic data and its projection

Financial viability
The estimate shall reflect the true scope, quantum and cost
of works based on detailed survey and investigations

				
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posted:5/9/2011
language:English
pages:33