A horizontal curve is designed for a four$-$lane highway $($lane width$=10$ft$.).$ The central angel is $40$ degrees. The PIA transportation engineer is designing a horizontal curve for a $2-$lane highway $($lane width$=10$ft$),$ with a $50$ degree

central angel. The design speed is $60mph$ and supperelevation is $6\%.$ What is the radius $($R$),$ and length of the curve

$(L)?$ What is the length of the tangent $($T$)?$

point is at $2600+00$ and the tangent distance is equal to $520ft.$ The side friction factor is $0\mathrm{.}08$ and superelevation is

$9\%.$ What is the stationing of PC and PT$?$ and what is the safe vehicle speed?