10.2.3.11 Grade-Separated
Grade separation is a method of aligning a junction of two or more roadways at different heights (grades) so that they will not disrupt the traffic flow on other routes when they cross each other. Grade separation is typically introduced for the major street through movement, while major street turning movements and all minor street movements still occur at the same grade. See for the basic features of a grade-separated intersection.

Figure 10-10: Grade Separated Features
Source: TxDOT Visual Dictionary - Grade Separation