Question

What will be the minimum visibility at vertical curves on National Highway?

(a) 130 m

(b) 200 m

(c) 20 m

(d) 100 m

The question was asked in unit test.

The query is from General Specifications of Modern Road topic in division Specifications, Estimation of Quantities of Materials and Transport of Civil Engineering Drawing

Answer 1

Correct option is (d) 100 m

Easiest explanation: The length of a crest vertical curve is governed by visibility considerations. The minimum length is based on the stopping sight distance; the maximum length is based on the passing sight distance, and overtaking is allowed throughout its length. The object of the present paper is theoretical determination of the zone of overtaking visibility in a curve designed on a below-maximum basis. The analysis covers 2 cases: (a) overtaking vehicle inside oncoming vehicle outside the curve and (b) both vehicles outside the curve. The corresponding curve geometries were also considered.