Question

The safe stopping sight distance on a flat highway section is 120 m and setback distance is of 12 m. The radius of the negotiable horizontal curve is

• A. 186 m
• B. 144 m
• C. 120 m
• D. 156 m

Answer 1

The correct option is D 156 m

By property of circle.

$\frac{L^2}{4}=(2R-12)\times 12$
$\Rightarrow \frac{{120}^2}{4}=12(2R-12)$
$\Rightarrow 300=2R-12$
$\Rightarrow R=156m$