QUESTION $4$

Traffic flow on a four$-$lane $($one direction$)$ freeway can be described by the Greenshields model. Two lanes of the four lanes of the four lanes on a section of this freeway will have to be closed to undertake an emergency bridge repair that is expected to take $2\mathrm{.}50$ hours. The mean free speed of the highway is $60m\frac{i}{h}$ and the jam density is $140ve\frac{h}{m}\frac{i}{ln}.$ If it is estimated that the demand flow on the highway during the emergency repairs is $80\%$ of the capacity, using the deterministic approach, determine:

$($i$)$ The maximum queue length that will be formed

$($ii$)$ The total delay

$($iii$)$ The number of vehicles that will be affected by the incident

$($iv$)$ The average individual delay

QUESTION $5$

A study of speed$-$flow$-$density relationships at a particular

freeway site has resulted in the following calibrated relationship:

$S=71\mathrm{.}5(1-\frac{D}{122})$

$S=$ Speed, $D=$ Density

Determine the free$-$flow speed and jam density for the relationship.

Derive the equations for speed versus flow and flow versus

density for this site.

Determine the capacity of the segment mathematically.