Problem 2 A developer is having a singlelane raceway constru

Problem 2: A developer is having a single-lane raceway constructed with a 200-mi/h design speed. A curve on the raceway has a radius of 4500 ft, a central angle of 30 degrees, and Pl stationing at 1125+10 If the design coefficient of side friction is 0.20, determine the superelevation required at the design speed. Also, compute the degree of curve, length of curve, and stationing of the PC and PT

Solution

a) Superelevation needed on a horizontal curve of 4500 ft i.e.1371.6 metre radius for a design speed of 200 mile/hour i.e.321.869 Km/h

is given by e+f=V^2/(127R)=321.86^2/(127*1371.60)=0.59

Thus e=0.59-f=0.59-0.20=0.39

Which is greater than 0.07,

So maximum superelevation provided is 0.07

b) Degree of curve=1718.90/R=1718.90/1371.60=1.25 degree

c)Length of curve=L=RTanTheta/2=1371.60*tan(30/2)=367.51 metre