Road Location in Dune Areas:
The following principle should be observed in locating a road in dune areas :
(a) Align a road where sand is covered by vegetation.
(b) Select a location where the sand is coarse and cannot be blown by wind.
(c) If a road has to be aligned parallel to a sand ridge, avoid locating the road on the slopes. Locate the road either at the top of the ridge or in the inter-dunal space.
(d) If possible locate the road away from the dune at a minimum distance of twice the dune height.
The details of the location of roads placed in dune areas are given in Figure.
Figure : Possible Locations of Road in Sand Ridge
The following guidelines may be observed in design :
(a) Avoid sections with partial cut and partial fill.
(b) Avoid cut sections as far as possible.
(c) Avoid high road embankments.
(d) When cutting is done in dunes, provide benchings 5-8 m wide.
(e) It is preferable to black-top the road, since unsurfaced pavements can get dislodged when the sand deposit is cleared by a grader.
(f) Precast concrete blocks are also be good surfacing specification since the cost of maintenance is minimised.