- There may be a variety of variations on the size and height of the top and bottom roundabout.
 
   
- Let’s take a look at some examples.  
   
 
   
Top: Overpass
Bottom: Ground-level
Top: Semi-overpass
Bottom: Semi-underpass
Top: Ground-level
Bottom: Underpass
 
   
   
 
   
Top: Overpass
Bottom: Ground-level
Top: Semi-overpass
Bottom: Semi-underpass
Top: Ground-level
Bottom: Underpass
 
   
   
 
   
Top: Overpass
Bottom: Ground-level
Top: Semi-overpass
Bottom: Semi-underpass
Top: Ground-level
Bottom: Underpass
 
   
- When a portion of the top roundabout is superimposed on the bottom roundabout, support for the top roundabout can take the staple shape() instead of a “T”.