California will inaugurate its first turbo-roundabout with the aim of reducing the number of traffic accidents. It is the first construction of its kind in that American state, but the solution has existed in Europe since the 90s, first introduced in the Netherlands, with positive results. Portugal, the second country in the world with the most roundabouts per million inhabitants (473.4), still does not have any “turbo” ones.
The main difference lies in the design with raised lane separators to prevent drivers from changing lanes too early, or avoiding the behavior we observe in so many drivers, which is to go through a roundabout with more than one lane on the outside, even if it goes through several exits. The correct thing to do in a roundabout is to use the inner lane, and only move to the right before your exit.
Turbo-roundabouts, where strategically placed separators force the driver to stay in the exact lane they should use until the desired exit, an idea from a university professor named Bertus Fortuijn, theoretically solve each of these setbacks. Problem: no one knows how to drive in them…
See here how a turbo-roundabout works: