1.3.3 - Create the Intersection
Step Description:
1. Do one of the following:
- Ribbon Home tab > Create Design panel > Intersections drop-down > Create Intersection command
- At the command line, enter CreateIntersection.

2. You are prompted to pick an intersection point in the drawing. Graphically select the location in the drawing where two alignments intersect.
NOTE: If you wish to create a 3-way intersection, it is important that the alignments meet precisely and do not overlap or undershoot. If the two alignments overlap, a 4-way intersection is created.
If you are creating a 4-way intersection, you will be prompted to select the alignment that will be identified as the primary road. If so, select the alignment by clicking the alignment in the drawing, or by pressing Enter and selecting from the list of alignments in the drawing.
If you are creating a T-shaped (3-way) intersection, then the alignment that passes through the intersection is automatically specified as the primary road (main road). In this situation, you are not prompted to specify which road is the primary road because this happens automatically. It is possible to change the road priority only during intersection object creation (on the Geometry Details page of the Create Intersection wizard).
AutoCAD Civil 3D 2012 User's Guide reference:
User's Guide - Corridor Modeling - Intersections and Roundabouts - Intersections - Creating Intersections - Using the Create Intersection Wizard
For more information watch the video below:
Create Intersection (WMV)