In some roundabouts, just relying on the “right of way” regulations results in long queues forming along the approaches. This usually happens when a roundabout suffers from unbalanced flow patterns (one or two of the approaches convey much heavier traffic compared to the others).
There is an idea that signalization of roundabouts can be useful as a countermeasure for such a problem, especially during peak hours. In that case, signal operation can come in many forms, including full-time control, part-time control, or metering.
One problem that seems to be facing engineers when signalizing roundabouts is lacking a general set of patterns or guidelines to choose an appropriate form of signalization and apply it efficiently in different situations. There is also a need for a comprehensive review over the available literature concerning signalization of roundabouts.
In this study, a review of literature regarding signalization of roundabouts is carried out. Moreover, a roundabout in Stavanger with unbalanced traffic flows is studied in order to find an appropriate signalization scenario which can improve the traffic situation. The network is modeled and simulated in AIMSUN.
Source: Linköping University
Author: Mosslemi, Marjan