Vehicles arrive according to a Poisson process $($random arrival$)$ to a parking lot

with mean arrival rate of $3$ vehicles $\frac{?}{\text{m}\text{i}\text{n}},$ and are processed $($they pay parking fee$)$ at a Poisson process

$($random Departure$)$ rate of $240$ vehicles$/$hour$.$

$(1)$ What type of queuing is this problem?

$\frac{D}{D}\frac{?}{1},\frac{M}{D}\frac{?}{1},\frac{M}{M}\frac{?}{1}$

$(2)$ What is the traffic intensity?

$(3)$ Determine $($I$)$ the average waiting time and $($II$)$ the average length of the queue.