A two$-$lane highway $($one $3\mathrm{.}6-m$ lane in each direction$)$ goes from normal

crown with $2\%$ cross$-$slopes to $8\%$ superelevation by means of a spiral tran$-$

sition curve. Determine the minimum length of the transition if the differ$-$

ence in grade between the centerline and edge of traveled way is limited to

$\frac{1}{200}.$ Round up to the next largest $20-m$ interval.