The intersection shown in Figure $21-15$ is to be analyzed using the HCM $2000$ methodology. All computations are to be done by hand but may be checked using any appropriate software.

$($a$)$ Determine the existing $\frac{v}{c}$ ratio and level of service for each lane group in the intersection.

$($b$)$ Determine the level of service for each approach and for the intersection as a whole.

$($c$)$ Make recommendations for improvements in the signal timing, if your results indicate that this is needed.

The following additional information is available concerning the intersection for Problem $21-2$: $PHF=0\mathrm{.}92$ : Arrival$-$types: $5WB,2EB,3NB$; $\%HV=12\%$ in all movements; no pedestriansoverpasses provided.

Figure $21\mathrm{.}15$: Data for Problem $21-2$