b$)$ A highway is being designed with an $86$ km$/$h design speed and at one section equaltangent vertical curve must be designed to connect grade of $+1\mathrm{.}5\%$ and $3\%.$Determine the minimum length of curve necessary to meet SSD requirement. $(5$ Marks$)$

c$)$ Calculate the length of SSD for a two$-$way traffic in a two$-$lane sloping road with adescending slope of $3\mathrm{.}2\%.$ The total time taken to react is $2\mathrm{.}5$ seconds, with a coefficientof friction f of $0\mathrm{.}35.$ The design speed is $77\mathrm{.}29$ km$/$h$.(5$ Marks$)$

d$)$ Find the rate of super elevation on a horizontal curve which has a radius of curvature$84$ m$.$ The design speed is $72\mathrm{.}48$ km$/$h and f $=0\mathrm{.}19.$ Also calculate the rise or bankingdue to super elevation if the road is $6\mathrm{.}8$ m$.$