A horizontal curve on a 4-lane highway (two lanes on each direction with no median) has a superelevation of 6% and a central angle of 40 degrees. The PT of the curve is at station 322+50 and the PI is at station 320+08. The road has 10ft lanes and 8ft shoulders on both sides with high retaining walls going up immediately next to the shoulders. What is the highest safe speed of this curve (highest in 5mph increments) and what is the station of the PC?