A simple highway curve is planned to connect two horizontal tangents that intersect at sta. 2500 + 00.00 at an external angle of 52 degrees. For a design speed of 60 mi/hr and a curve radius of about 1.25 times the minimum allowable, calculate
(a) the design rate of superelevation and (b) the required length of superelevation runoff.
Assume a four-lane undivided highway and 10-ft lanes. Clearly state any other assumptions that you think are needed.