QUESTION $1$

$[10$ MARKS$]$

$1\mathrm{.}1.$ Detailed geotechnical investigations should be carried out once the route has been staked out. Discuss the type of methods and procedures used to obtain fleld samples for the following geotechnical investigations.

$1\mathrm{.}2$ The ADT for an urban road is $18,000$ vehicles per day. Assume a k$-$factor of $12\%$ and a D of $60\%.$

$(4)$

$1\mathrm{.}2\mathrm{.}1$ Determine the DHV in the design direction.

$1\mathrm{.}2\mathrm{.}2$ How is the DHV used to determine the required number of lanes in each direction?