AutoTURN Feature (Vertical and 3D Simulation) - What is the difference between the Vertical and 3D Simulation tools?

While both tools are used to flag potential conflicts along the vehicle's profile, the Vertical Simulation tool is a simplified solution where the vehicle's wheels travel along the same axle and along a constant slope.  Meanwhile, the 3D Arc Path tool flags potential conflicts against a 3D terrain while considering slope changes along the surface.