Question

Calculate the extra width of pavement required on a horizontal curve of radius 700m

on a two-lane highway, the design speed being 80 kmph. Assume wheel base l = 6m.

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Answer 1

Given:

R = 700m

l=6 m

n = 2

V= 80 kmph

Extra widening of road is given by

$\begin{array}{l}W_{e}=W_{m}+W_{p s} \\end{array}$

$W_{e}=\frac{n l^{2}}{2 R}+\frac{V}{9.5 \sqrt{R}}$

put values in formula

$W_{e}=\frac{2 \times(6)^{2}}{2 \times 700}+\frac{80}{9.5 \times \sqrt{700}}$

$W_{e}=\frac{36}{700} + \frac{80}{9.5\times 26.45 }$

$W_{e}=0.051+\frac{80}{250.8}$

$W_{e}=0.051+0.318$

$W_{e}=0.36$ m

Hence the answer is 0.36 m