Roundabouts are often used to reduce congestion, but conventional UK designs aren’t cycle-friendly (or pedestrian-friendly). The Dutch have developed a design for an urban cycle-friendly roundabout, but it takes quite a lot of space. The full design has a completely-circular cycle track, set back from the roundabout by 5m (one car-length). The minimum size for the roundabout itself is 25m diameter, with a 13m island. Including pavements, you need a minimum 45m diameter.
This is a sketch design for the junction where Barns Road meets Between Towns Road in Cowley, Oxford. The junction is moderately busy, and is currently a mini-roundabout with a bypass lane. The roads in the area are unnecessarily wide, and there are no reasonable quiet routes. So it makes sense to provide segregated cycle tracks along Between Towns Road, and make the junctions as cycle-friendly as possible.
A full Dutch roundabout doesn’t fit, but by judiciously distorting the circular cycle track, it can just about be squeezed in. It is important that the cycle track splits several metres before each crossing, and cyclists approaching the crossing shouldn’t have any sharp turns. This makes it clear to motorists that the cyclist is crossing, and they should give way.
The roadway had to be extended by a few metres northwards at the junction, into a grassed area. The original aerial imagery is from Google Maps.