A two$-$lane road possesses the flow$-$density relationship shown below. Based on this information, determine $($i$)$ the jam density, $($ii$)$ the capacity of the road, $($iii$)$ the free$-$flow speed, $($iv$)$ the speed at capacity $($v$)$ the possible speeds when the flow is $3,000$ veh$/$h$,$ and $($vi$)$ the level of service for the two possible speeds from $($v$).$

q $=120$k $0\mathrm{.}6$k$^2$