That is a compact roundabout rather than a turbo roundabout, but the principle is the same - use tight geometry in order to reduce traffic speeds. It will the second example in Cambridge following this one:
https://www.ucl.ac.uk/transport-institute/pdfs/alasdair_massieThat has seen a dramatic improvement to safety at what used to be an accident black spot.
The lower speeds benefit ALL users and makes it safer for everyone.
For cyclists riding on the carriageway (which is what these designs are principaly aimed at) it is much more friendly.
For pedestrians or cyclists using the zebra crossings become much easier to cross.
It even makes it easier for drivers trying to join the roundabout to judge a safer gap in the traffic.
The proposal for the turbo in Cambridge I would presume is on the back of this by TRL
http://www.bbc.co.uk/news/uk-england-london-22350776 which I thought I remembered one of the forum posters here going on or was at least one of those that were used by TRL
That it still had a near miss in perfect conditions, riders wearing hi-vis, no distractions, all drivers instructed beforehand, low levels of traffic, during the day highlights the flaws in the design.
Yes, that is the video - at about 2 minutes in.
What It shows the inherent flaws of orbital cycle paths crossing the entry and exit arms of roundabouts, rather than a problem with compact geometry - while that was a near miss in those conditions, a similar orbital path crossing the entry/exit arms of a conventional high-speed UK geometry roundabout would be lethal. Even the Dutch now make cycle paths yield priority in these sorts of situations due to safety concerns.