Market towns often have a single-carriageway ring road or bypass with roundabouts. This will usually cross the route between nearby villages and the town, for instance for going to secondary school, visiting friends or shopping.
Speeds will typically be 40mph, with flared entries and exits, and these roundabouts are not-at-all pedestrian or cycle-friendly. A Toucan crossing could be provided a little way from the roundabout, but this will typically be considerably slower than risking the roundabout, as well as moderately expensive. The junction could be converted to traffic lights, but this costs even more.
This is a sketch drawing for the Wootton Road roundabout north of Abingdon. The design is close to the Dutch standard design for such situations, with bottle-shaped islands on each arm to slow the traffic down, and cyclists on tracks, giving way to cross each arm. Most cyclists will go north-south, and will have to give way twice in quick succession at relatively stress-free crossings. This compares reasonably to having to give way once to enter the roundabout.
The green areas are road that would be returned to grass. The existing cycle tracks/pavements and crossing points have been used.
The original aerial imagery is from Google Maps.