- The conventional roundabout has been split into two levels by directing traffic from 4 directions to top and bottom levels.

- Intersecting points of traffic flow are reduced significantly as vehicles traffic is divided into top and bottom levels as they enter the intersection.

- Vehicles enter the roundabout to the top and bottom, so the number of vehicles passing through each roundabout is reduced to increase traffic flow.

 
   
 
   

- Traffic from 4 directions enters the roundabout at the same time.

- In such case, smooth flow of traffic is possible when there are few vehicles entering the roundabout, but beyond certain point, efficiency falls drastically.

- The diagram on the right illustrates traffic flow in the conventional roundabout. As seen in the illustration, there is a total of 12 points where vehicles cross paths.

 
   
   
 
   
- Let’s separate and look at the flow of traffic entering the roundabout from east-west, and from north-south independently.  
   
 
   
- shows the part of the road used by traffic entering the roundabout from east-west directions.
 
- shows the part of the road used by traffic entering the roundabout from north-south directions.  
   
   
- The following is the “two-level roundabout” developed by Roadnext by making Diagram 1 as the top level and Diagram 2 as the bottom level.  
   
 
   
- The Two-Level Round-About by Roadnext has only two points of conflict, which significantly reduces crossing of vehicles compared with the conventional roundabout.  
   
 
   
- Furthermore, it significantly reduces the number of vehicles entering each roundabout.  
   
For example, if the number of vehicles entering the conventional roundabout is 10 vehicles per minutes from each of the 4 directions, then the number of vehicles passing through the roundabout is 40 vehicles per minute (10 X 4)
However, under the same condition, the number of vehicles entering the two-level roundabout is 20 per each level (10 X 2).
As such, 40 vehicles are involved in 12 points of conflict per minute in the conventional roundabout. However, in the Two-Level Round-About, 20 vehicles are involved in 2 points of conflict per minute per each level.
Please note that there may be varying possibilities, as this is a simplified example to explain the number of points of vehicle conflict.
 
   
- Furthermore, vehicles making U-turns and circling the roundabout more than once have been omitted for easier understanding.  
   
- The Two-Level RoundAbout can be also applied to 5-way intersection.