a$).$ A vertical curve is designed to provide safe stopping sight distance. The PVC of the curve is at station

$1+234\mathrm{.}000$ with elevation of $1100m$ while the PVI is at station $1+324\mathrm{.}000($elevation $1100m).$ The

elevation at PVT is $1102\mathrm{.}00m.$ Based on the AASHTO design standard, is the curve adequate for a

design speed of $100k\frac{m}{h}?$ Why or why not?

b$).$ You are asked to locate a directional sign near the exit of a freeway ramp. How far should

the directional sign be placed ahead of the exit of the freeway ramp? The following

information is available for your analysis:

The freeway has a posted speed of $120k\frac{m}{h}$ and the posted ramp speed is $30k\frac{m}{h}$;

Past research experiments indicated that most drivers can read a traffic sign within his or

her area of vision at a distance of $50$ meters when traveling at a speed of $120k\frac{m}{h},$ and

need $1$ second to complete their reading and $1$ second to decide and react $($i$.$e$.,$ press brake

to slow down if they want to exit$)$;

The highway section is on a $2\%$ downgrade with a coefficient of road adhesion of $0\mathrm{.}60$ and

a coefficient of friction of $0\mathrm{.}28.$