$21-3-21-7.$ Develop a signal design and timing for the inter$-$

sections shown in Figures $21\mathrm{.}21$ to $21\mathrm{.}25.$ In each cas.

accommodate both vehicular and pedestrian needs.

Where necessary to make assumptions on key values

state these explicitly. If a successful signal tining

requires geometric changes, indicate these with an

appropriate drawing.

In general, the following values should be unit

for all problems:

All volumes are in veh$/$h

Pedestrian walking speed $=4\mathrm{.}0f\frac{t}{s}$

: Vehicle deceleration speed $=10\mathrm{.}0f\frac{t}{s^2}$

Driver reaction time $=1\mathrm{.}0s$

Length of typical vehicle $=20ft$

Level grades unless otherwise indicated

You only need to find $PHF=0\mathrm{.}90$

Target$\frac{v}{c}=0\mathrm{.}95$

Low pedestrian activity

Average approach speeds:

$,40m\frac{i}{h}B$

$50m\frac{i}{h}NB$

Crosswalk widths $=10ft$

$NB$ grade $=3\%$

$WB$ grade $=-1\%$

Figure $21\mathrm{.}21$: Intersection for Problem $21-3$ cycle length, effective green times, and green time

calculations