Includes collecting, transporting, and disposing of surface/subsurface water originating on or near the highway right of way or flowing in streams crossing bordering that right of way. Drainage of highway is important because water damage highway structure in many ways. The water which are dangerous for highways are: Rainwater: Cause erosion on surface or may

In triangulation the base line is of prime importance because it is the only horizontal distance to be measured. It should be measured very accurately since the accuracy of the computed sides of triangulation system depends on it.

Correction for sag is the deference in length between the are and its chord i.e b/t the curved length of the laps and the distance between the supports. It’s us required only when the tape is suspended during measurement.

The line of sight should not be near the surface of ground at pt of tangency on account of strata of disturbed air and should be kept at least 2m (61) above the ground preferably 3m (1D) and this allowance (clearance) should be made in deterring the heights of stations. If the peaks in the intervening ground are likely to obstruct, the line of sight, their elevations and

Geodetic or trigonometrically surveying takes into account the curvature of earth Since very extensive areas and very large distances are involved. In geodetic surveying highly refined instruments and methods are used. Geodetic work is undertaken by the state agency e.g. survey of Pakistan undertaken by the state agency. The object of geodetic surveying is to