TPG$3700$ Assignment $1-02/04/2024$

$1\mathrm{.}8$ The sketch below shows design data for a three phase, pre$-$timed signal of an at$-$grade intersection. Assume total lost time per phase equals to $3sec,$ yellow time $=3$ sec per phase, clearance time $=2$ sec per phase. Ignore pedestrians. Use Webster's equation to estimate the optimal cycle length. Round up to the nearest $10$ and determine green time allocation for each phase.

$(11)$

$[$ou naris$]$

Question $2$

$2\mathrm{.}1$ Briefly explain the purpose of directional islands in an at$-$grade intersection.

$2\mathrm{.}2$ What is the main reason of avoiding at$-$grade intersections near a horizontal curve or on a crest curve.

$2\mathrm{.}3$ A newly constructed road has been identified to cause unacceptable noise on nearby building. You have been tasked to plan a noise barrier wall. Briefly explain four design aspects you will consider for the barrier design.

$2\mathrm{.}4$ Briefly explain measures you would take to mitigate the effect of erosion for a box culvert that pass beneath the embankment of a rural foad in $KZN.$ Also, explain the implication$($s$)$ if erosion is not taken care of tor the road thereof.

$3$ of $8$