The radius of a horizontal circular curve on a highway is $120$ m. The design speed is $60$ km/hour, and the design coefficient of lateral friction between the tyre and road surface is $0.15$. The estimated value of superrelevation required (if full lateral friction is assumed to develop), and the value of coefficient of friction needed (if no superrelevation is provided) will, respectively, be

1. $\dfrac{1}{11.6} \text{ and } 0.10 \\$
2. $\dfrac{1}{10.5} \text{ and } 0.37 \\$
3. $\dfrac{1}{11.6} \text{ and } 0.24 \\$
4. $\dfrac{1}{12.9} \text{ and } 0.24$