add information regarding number of arcs in graph.

src/main/org/insa/graph/GraphStatistics.java

     // Bounding box for this graph.
     private final BoundingBox boundingBox;
 
+    // Number of roads
+    private final int nbRoadOneWay, nbRoadTwoWays;
+
     // Maximum speed on this graph (in kmph).
     private final int maximumSpeed;
 
      * Create a new GraphStatistics instance with the given value.
      * 
      * @param boundingBox Bounding-box for the graph.
+     * @param nbRoadOneWay Number of one-way roads in the graph.
+     * @param nbRoadTwoTayws Number of two-ways roads in the graph.
      * @param maximumSpeed Maximum speed of any road of the graph. You can use
      *        {@link #NO_MAXIMUM_SPEED} to indicate that the graph has no maximum
      *        speed limit.
      * @param maximumLength Maximum length of any arc of the graph.
      */
-    public GraphStatistics(BoundingBox boundingBox, int maximumSpeed, float maximumLength) {
+    public GraphStatistics(BoundingBox boundingBox, int nbRoadOneWay, int nbRoadTwoWays,
+            int maximumSpeed, float maximumLength) {
         this.boundingBox = boundingBox;
+        this.nbRoadOneWay = nbRoadOneWay;
+        this.nbRoadTwoWays = nbRoadTwoWays;
         this.maximumLength = maximumLength;
         this.maximumSpeed = maximumSpeed;
     }
     }
 
     /**
+     * @return Amount of one-way roads in this graph.
+     */
+    public int getOneWayRoadCount() {
+        return this.nbRoadOneWay;
+    }
+
+    /**
+     * @return Amount of two-ways roads in this graph.
+     */
+    public int getTwoWaysRoadCount() {
+        return this.nbRoadTwoWays;
+    }
+
+    /**
+     * @return Number of arcs in this graph.
+     * 
+     * @see #getOneWayRoadCount()
+     * @see #getTwoWaysRoadCount()
+     */
+    public int getArcCount() {
+        return getOneWayRoadCount() + 2 * getTwoWaysRoadCount();
+    }
+
+    /**
      * @return true if this graph has a maximum speed limit, false otherwise.
      */
     public boolean hasMaximumSpeed() {

src/main/org/insa/graph/io/BinaryGraphReader.java

         // Read successors and convert to arcs.
         float maxLength = 0;
         final int copyNbTotalSuccesors = nbTotalSuccessors; // Stupid Java...
+        int nbOneWayRoad = 0;
         observers.forEach((observer) -> observer.notifyStartReadingArcs(copyNbTotalSuccesors));
         for (int node = 0; node < nbNodes; ++node) {
             for (int succ = 0; succ < nbSuccessors[node]; ++succ) {
 
                 // Add successor to initial arc.
                 Arc arc = Node.linkNodes(orig, dest, length, info, points);
+                if (info.isOneWay()) {
+                    nbOneWayRoad++;
+                }
                 observers.forEach((observer) -> observer.notifyNewArcRead(arc));
             }
         }
         this.dis.close();
 
         return new Graph(mapId, mapName, nodes,
-                new GraphStatistics(new BoundingBox(new Point(minLongitude, maxLatitude),
-                        new Point(maxLongitude, minLatitude)), maxSpeed, maxLength));
+                new GraphStatistics(
+                        new BoundingBox(new Point(minLongitude, maxLatitude),
+                                new Point(maxLongitude, minLatitude)),
+                        nbOneWayRoad, nbTotalSuccessors - nbOneWayRoad, maxSpeed, maxLength));
     }
 
     /**

src/main/org/insa/graphics/MainWindow.java

                     // name that are right-to-left (e.g. arabic names).
                     info += " - " + graph.getMapName() + "\u200e";
                 }
-                info += ", " + graph.getNodes().size() + " nodes";
+                info += ", " + graph.getNodes().size() + " nodes, "
+                        + graph.getGraphInformation().getArcCount() + " arcs.";
                 graphInfoPanel.setText(info);
 
                 drawGraph();