Question

The value of absolute minimum radius of horizontal curve on a national highway in plain terrain will be _______ m.
[Consider minimum design speed as 80 kmph]

• A. 202
• B. 120
• C. 265
• D. 229

Answer 1

The correct option is D 229

Absolute minimum radius,
$R_{min}=\frac{V^2}{127(e+f)}$

where, V = 80 km/hr (For NH in plain terrain)
e = 0.07, f = 0.15 (As per IRC)

$\therefore R_{min}=\frac{{\left(80\right)}^2}{127(0.07+0.15)}=229.06m$