Question $2$:

Consider a four$-$way signalized intersection with the following geometric conditions and arrival vehicular flows in $pc\frac{u}{h}$ as shown below. Assume the following conditions are observed:

Eastbound and westbound left turns are protected.

Northbound and southbound left turns are not protected $($permitted$).$

The saturation flow rates in the protected left turn lanes and through$/$right turn lanes are $1900pc\frac{u}{h}$ and $1800pc\frac{u}{h},$ respectively.

Amber of $3s$ follows the protected left turn green interval.

Amber of $3s$ and all red of $1s$ follow the through movement green interval.

Pedestrian walking speed is $1\frac{m}{s}$ and pedestrian clearance time is $6s$ for N$-$S crosswalks and $3s$ for E$-$W crosswalks

a$)$ Determine the designed signal timing.

b$)$ Determine whether the capacity at this signalized intersection is enough to handle the traffic using the critical movement analysis method.

c$)$ If the above intersection is considered isolated, determine the Level of Service $($LOS$)$ if the arrival flows listed above were observed over a period of $30$ minutes.