In OpenStreetMap, it is very common to have roundabout represented as a unique closed way. This roundabout may then be used as part as bus route relations.
Even if it is cleaner to cut the roundabout in separate ways at each relevant intersection to have a continuous bus route, using a closed way of the entire roundabout in the relation is usually not considered an error in OpenStreetMap.
But osm2gtfs does fail to generate the shape because of the closed way.
For instance, for this bus route
the shape generated is cut at the first un-cut roundabout met:
A valid fix would be to ignore and skip closed way on the shape building.
In OpenStreetMap, it is very common to have roundabout represented as a unique closed way. This roundabout may then be used as part as bus route relations.
Even if it is cleaner to cut the roundabout in separate ways at each relevant intersection to have a continuous bus route, using a closed way of the entire roundabout in the relation is usually not considered an error in OpenStreetMap.
But osm2gtfs does fail to generate the shape because of the closed way.
For instance, for this bus route
the shape generated is cut at the first un-cut roundabout met:
A valid fix would be to ignore and skip closed way on the shape building.