A horizontal curve is being designed through mountainous terrain for a four-lane road with lanes that are 10 ft wide. The central angle (?) is known to be 40 degrees, the tangent distance is 520 ft, and the stationing of the tangent intersection (PI) is 2600 + 00.
Under specified conditions and vehicle speed, the roadway surface is determined to have a coefficient of side friction of 0.08, and the curve's super elevation is 0.09 ft/ft. What is the stationing of the PC and PT and what is the safe vehicle speed?