The table below gives $K$ values that may be used in the formula $(L=K|p-q|$ used to determine the length of vertical crest or sag curves on a highway. The gradient as a road approaches a vertical curve $($p$)$ is $-1\%$ and the gradient leaving the curve $($q$)$ is $+2\%,$ whilst the absolute minimum curve length is $39$ metres. What should the speed limit be$?$

$\backslash$table$[[,$Design speed $(k\frac{m}{h}r)$