OUESTION $4(25$ MARKS$)$

a$)$ Explain sight distance giving its significance and the different types, and the factors

affecting its computation.

$8$marks

b$)$ Compute the minimum length of vertical curve that will provide $190$ m stopping sight

distance for a design speed of $100k\frac{m}{h}$ at the intersection of a $+2\mathrm{.}60\%$ grade and a $-$

$2\mathrm{.}40\%$ grade.

c$)$ Given $V=80kmph,R=200m$ Design for super elevation. $f=0\mathrm{.}15.6$marks

d$)$ Find the extra widening for $R=250m,$ longest wheel base, $l=7m,V=70kmph,n=2.$