Turbo-roundabout (originally Turborotonde) was created in the early 90s and its authorship is attributed to the Dutch professor Lambertus GH Fortuijn. In essence, it is a visually more complex roundabout, or rather a special type with a spiral arrangement and often physically separated lanes.
At first glance, it really looks complicated, but in reality it was created just to simplified the use of multi-lane roundabouts, increased traffic capacity in a given location and, above all, increased traffic safety.
The essence of the design of the turbo circuit is that it reduces the interaction between vehicles and at the same time reduces the total number of collision points.
If we have a roundabout with four two-lane branches, according to the study, the number of collision points will be reduced from 24 to 14, but in reality the difference is even greater, because on a regular multi-lane roundabout, cars can theoretically crash into each other anywhere on the perimeter, not just at the intersection .
In this case, too, it is valid that cars going through the roundabout have priority over vehicles entering it (note the exception with the continuous lane, which is usually physically separated on turbo-circuits).
It is then important to remember that you must have a clearly thought out direction of travel before using the turbo roundaboutso it is necessary to choose the appropriate lane in advance. In this, drivers are helped by horizontal and vertical traffic markings used well in advance of the incriminated place. The reason is the fact that lane selection then determines which particular exits you will be able to use.
Scarecrow just to look at
The rest is not a science, and moreover, the use of turbo roundabouts has proven itself extremely well. You can find hundreds of them in the Netherlands (Turborotonde) or Germany (under the name Turbokreisverkehr), dozens more are created in Poland (Rondo turbinowe), they also work successfully in the neighboring Czech Republic, although it must be added, due to the habit and mistakes in traffic signs (more precisely due to its deployment in insufficient advance) crisis situations arose and occasionally still arise for example in České Budejovice or Pilsen.
But enough of the theory. If you do not have experience with the turbo-circular bypass, a couple of attached videos will explain how easy it is to use.
In the following video, from 9 minutes 30 seconds, you will find, among other things, errors in the use of the turbo roundabout