[throw0101d]

> They are a liability when traffic levels are high enough - say during peak times - when one inbound direction is blocked by another.

It is possible to add traffic signals to roundabouts (in the UK the standard is TD 50 (DMRB 6.2.3)):

* https://en.wikipedia.org/wiki/Roundabout#Signalised_roundabo...

* http://www.jctconsultancy.co.uk/Consultancy/roundabouts.php

* https://assets.publishing.service.gov.uk/media/5e81b669e90e0...

If one direction dominates, you can stop it and then let the others have a turn.