There are several of these near where I live (in the UK) but I've never heard the term "burger lanes" before. We don't seem to have a name for them - they just are!
They serve the same basic function as a roundabout with a flyover bridge, except that all the roads are on the same level. The intersections of the burger lane and the roundabout are controlled by traffic lights.
They have an advantage where the main traffic flow is different at different times of day (e.g. during the commuting rush hours) - for example traffic can move faster across the "burger lane" than negotiating the sharper curves entering and leaving the roundabout itself, if the roundabout is relatively small and there is no space available to enlarge it.
For example here's one on Google Maps where there is a "burger lane" on the north-east bound carriage way of the dual-carriageway A52 (to avoid driving round most of the roundabout) but not on the south-west bound carriageway, which only passes one intersection on the roundabout - and that road, "Town St," has a negligible amount of traffic compared with the A6007 "Ilkeston road" on the other side.