Index: /applications/editors/josm/plugins/pt_assistant/src/org/openstreetmap/josm/plugins/pt_assistant/PTAssistantPlugin.java
===================================================================
--- /applications/editors/josm/plugins/pt_assistant/src/org/openstreetmap/josm/plugins/pt_assistant/PTAssistantPlugin.java	(revision 33398)
+++ /applications/editors/josm/plugins/pt_assistant/src/org/openstreetmap/josm/plugins/pt_assistant/PTAssistantPlugin.java	(revision 33399)
@@ -21,4 +21,5 @@
 import org.openstreetmap.josm.plugins.pt_assistant.actions.EditHighlightedRelationsAction;
 import org.openstreetmap.josm.plugins.pt_assistant.actions.RepeatLastFixAction;
+import org.openstreetmap.josm.plugins.pt_assistant.actions.SplitRoundaboutAction;
 import org.openstreetmap.josm.plugins.pt_assistant.data.PTRouteSegment;
 import org.openstreetmap.josm.plugins.pt_assistant.gui.PTAssistantPreferenceSetting;
@@ -62,6 +63,7 @@
         RepeatLastFixAction repeatLastFixAction = new RepeatLastFixAction();
         EditHighlightedRelationsAction editHighlightedRelationsAction = new EditHighlightedRelationsAction();
-        repeatLastFixMenu = MainMenu.add(Main.main.menu.toolsMenu, repeatLastFixAction, false);
-        editHighlightedRelationsMenu = MainMenu.add(Main.main.menu.toolsMenu, editHighlightedRelationsAction, false);
+        repeatLastFixMenu = MainMenu.add(Main.main.menu.toolsMenu, repeatLastFixAction);
+        editHighlightedRelationsMenu = MainMenu.add(Main.main.menu.toolsMenu, editHighlightedRelationsAction);
+        MainMenu.add(Main.main.menu.toolsMenu, new SplitRoundaboutAction());
     }
 
Index: /applications/editors/josm/plugins/pt_assistant/src/org/openstreetmap/josm/plugins/pt_assistant/actions/SplitRoundaboutAction.java
===================================================================
--- /applications/editors/josm/plugins/pt_assistant/src/org/openstreetmap/josm/plugins/pt_assistant/actions/SplitRoundaboutAction.java	(revision 33399)
+++ /applications/editors/josm/plugins/pt_assistant/src/org/openstreetmap/josm/plugins/pt_assistant/actions/SplitRoundaboutAction.java	(revision 33399)
@@ -0,0 +1,145 @@
+package org.openstreetmap.josm.plugins.pt_assistant.actions;
+
+import static org.openstreetmap.josm.tools.I18n.tr;
+
+import java.awt.event.ActionEvent;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+
+import javax.swing.JOptionPane;
+
+import org.openstreetmap.josm.Main;
+import org.openstreetmap.josm.actions.AlignInCircleAction;
+import org.openstreetmap.josm.actions.JosmAction;
+import org.openstreetmap.josm.actions.SplitWayAction;
+import org.openstreetmap.josm.actions.downloadtasks.DownloadOsmTask;
+import org.openstreetmap.josm.data.Bounds;
+import org.openstreetmap.josm.data.osm.BBox;
+import org.openstreetmap.josm.data.osm.Node;
+import org.openstreetmap.josm.data.osm.OsmPrimitive;
+import org.openstreetmap.josm.data.osm.OsmPrimitiveType;
+import org.openstreetmap.josm.data.osm.Relation;
+import org.openstreetmap.josm.data.osm.RelationMember;
+import org.openstreetmap.josm.data.osm.Way;
+import org.openstreetmap.josm.plugins.pt_assistant.utils.RouteUtils;
+
+/*
+ */
+public class SplitRoundaboutAction extends JosmAction {
+
+	private static final String actionName = "Split Roundabout";
+
+	private static final long serialVersionUID = 8912249304286025356L;
+
+	public SplitRoundaboutAction() {
+		super(actionName, "icons/splitroundabout", actionName, null, true);
+	}
+
+	@Override
+	public void actionPerformed(ActionEvent e) {
+		Way roundabout = (Way) getLayerManager().getEditDataSet().getSelected().iterator().next();
+
+		//download the bbox around the roundabout
+		DownloadOsmTask task = new DownloadOsmTask();
+        task.setZoomAfterDownload(true);
+        BBox rbbox = roundabout.getBBox();
+        double latOffset = (rbbox.getTopLeftLat() - rbbox.getBottomRightLat()) / 10;
+        double lonOffset = (rbbox.getBottomRightLon() - rbbox.getTopLeftLon()) / 10;
+        Bounds area = new Bounds(
+        		rbbox.getBottomRightLat() - latOffset,
+        		rbbox.getTopLeftLon() - lonOffset,
+        		rbbox.getTopLeftLat() + latOffset,
+        		rbbox.getBottomRightLon() + lonOffset);
+        Future<?> future = task.download(false, area, null);
+        Main.worker.submit(() -> {
+        	try {
+				future.get();
+				continueAfterDownload(roundabout);
+			} catch (InterruptedException | ExecutionException e1) {
+			 	Main.error(e1);
+				return;
+			}
+        });
+	}
+
+	private void continueAfterDownload(Way roundabout)
+	{
+		//make the roundabout round, if requested
+		int result = JOptionPane.showOptionDialog(Main.parent,
+				tr("Do you want to make the roundabout round?"), tr("Roundabout round"),
+				JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE,
+				null, null, null);
+
+		if(result == JOptionPane.YES_OPTION) {
+			new AlignInCircleAction().actionPerformed(null);
+		}
+
+		//save the position of the roundabout inside each relation
+		Map<Relation, Integer> savedPositions = new HashMap<>();
+		List <OsmPrimitive> referrers = roundabout.getReferrers();
+		referrers.removeIf(r -> r.getType() != OsmPrimitiveType.RELATION
+				|| !RouteUtils.isTwoDirectionRoute((Relation) r));
+		for(OsmPrimitive currPrim : referrers) {
+			Relation curr = (Relation) currPrim;
+			for(int j = 0; j < curr.getMembersCount(); j++) {
+				if(curr.getMember(j).getUniqueId() == roundabout.getUniqueId()) {
+					savedPositions.put(curr, j);
+					curr.removeMember(j);
+					break;
+				}
+			}
+		}
+
+        //split the roundabout
+		List<Node> splitNodes = roundabout.getNodes();
+		splitNodes.removeIf(n -> n.getParentWays().size() != 2);
+		getLayerManager().getEditDataSet().setSelected(splitNodes);
+		new SplitWayAction().actionPerformed(null);
+		Collection<OsmPrimitive> splittedWays = getLayerManager().getEditDataSet().getSelected();
+
+        //update the relations
+		savedPositions.forEach((r, i) -> {
+			Way previous = r.getMember(i-1).getWay();
+			Way next = r.getMember(i).getWay();
+			if(splitNodes.contains(previous.lastNode()) && splitNodes.contains(next.firstNode())) {
+				//lucky case: the ways were in order and the whole left by
+				//removing the roundabout can be easily filled with the splitted
+				//segment(s) that has as the first and last node the two just checked
+
+				List<Way> parents = previous.lastNode().getParentWays();
+				parents.removeIf(w -> !w.firstNode().equals(previous.lastNode()));
+
+				Way curr = parents.get(0);
+				int j = 0;
+
+				while(!curr.lastNode().equals(next.firstNode())) {
+					r.addMember(i + j++, new RelationMember(null, curr));
+					parents = curr.lastNode().getParentWays();
+					parents.remove(curr);
+					parents.removeIf(w -> !splittedWays.contains(w));
+					curr = parents.get(0);
+				}
+				r.addMember(i + j++, new RelationMember(null, curr));
+			}
+		});
+	}
+
+	@Override
+	protected void updateEnabledState(
+			Collection<? extends OsmPrimitive> selection) {
+        setEnabled(false);
+		if (selection == null || selection.size() != 1)
+            return;
+		OsmPrimitive selected = selection.iterator().next();
+	    if(selected.getType() != OsmPrimitiveType.WAY)
+        	return;
+        if(((Way)selected).isClosed() && selected.hasTag("junction", "roundabout")) {
+        	setEnabled(true);
+        	return;
+        }
+	}
+}