Question

Calculate the maximum permissible speed on a horizontal curve of radius 125 m of a highway, designed for a speed of 65 kmph. If the superelevation is restricted to 7%. Take the permissible value of the friction coefficient as 0.15

• A. 59.13
• B. 65
• C. 47.30
• D. 116.22

Answer 1

The correct option is A 59.13

Maximum permissible speed will be calculated by taking maximum superelevation and permissible value of friction.

$\Rightarrow e+f=\frac{v^2}{gr}$
$\Rightarrow 0.07+0.15=\frac{v^2}{9.81\times 125}$
$\Rightarrow 0.22=\frac{v^2}{1226.25}$
$v=16.424m/s$
$V=59.13kmph$
V is less than the design speed of 65 kmph hence permissible maximum speed is 59.13 kmph