Problem $1)$ Temporal capacity reduction

You have a three$-$lane automobile$-$only road, which is designed with a free$-$flow speed of $80(k\frac{m}{h}),$ a capacity of $2000($veh$/$h$/$lane$),$ and a maximum jam density of $150($veh$/$km$/$lane$).$ Vehicle demand is constant at $2500($veh$/$h$).$ At $30$ minutes after observation $(t=0\mathrm{.}5),$ an incident occurs at $10km$ of the road