Which one of the following pairs is correctly matched? (Notations have their usual meaning)
1
To avoid both skidding and overturning \( \ldots \frac{P}{W} \le \frac{b}{{2h}} \le f\)
2
Allowable maximum super elevation in plain region ……. 0.15
3
Allowable coefficient of lateral friction ….. 0.07
4
Attainment of superelevation \(\ldots \frac{{n{l^2}}}{{2R}}\)