(10 points) a highway reconstruction project is being undertaken to reduce crach rates. the reconstruction involves a major realignment of the highway such that a 60 mph design speed is attained. at one point on the highway, a 720-ft equal tangent crest vertical curve exists. measurements show that at 3+40 stations from pvc, the vertical curve offset is 3.5 ft. assess the adequacy of this existing curve in light of the reconstruction design speed of 60 mph and if the existing curve is inadequate, compute a satisfactory curve length.