Two straight sections of freeway cross at a right angle. At the point of crossing, the east-west highway is at elevation 150 ft and is a constant +5.0% grade (upgrade in the east direction), the north-south highway is at elevation 125 ft and is a constant -3.0% grade (downgrade in the north direction). Design a 90-degree ramp that connects the northbound direction of travel to the eastbound direction of travel.
Design the ramp for the highest design speed (to the nearest 5 mph) without exceeding a minimum D of 8.0. (Assume the PC of the horizontal curve is at station 15+00, and the vertical curve PVIs are at the PC and PT of the horizontal curve). Maximum allowed superelevation by design standards is 12%.
Determine the following:
Stationing and elevations of the horizontal curve PC and PT
Horizontal curve radius and length
Stationing and elevations of the vertical curve PVCs and PVTs
Vertical curve lengths
Length of constant grade in between the 2 vertical curves (if any)