diff --git a/src/main/org/insa/algo/datastructures/BinaryHeap.java b/src/main/org/insa/algo/datastructures/BinaryHeap.java
index a987cd9..55c1a5b 100644
--- a/src/main/org/insa/algo/datastructures/BinaryHeap.java
+++ b/src/main/org/insa/algo/datastructures/BinaryHeap.java
@@ -9,244 +9,205 @@
 
 package org.insa.algo.datastructures;
 
-import java.util.* ;
+import java.util.ArrayList;
 
 /**
- * Implements a binary heap.
- * Note that all "matching" is based on the compareTo method.
+ * Implements a binary heap. Note that all "matching" is based on the compareTo
+ * method.
+ * 
  * @author Mark Allen Weiss
  * @author DLB
  */
 public class BinaryHeap<E extends Comparable<E>> {
 
-	private int currentSize; // Number of elements in heap
+    private int currentSize; // Number of elements in heap
 
-	// Java genericity does not work with arrays.
-	// We have to use an ArrayList
-	private ArrayList<E> array; // The heap array
+    // Java genericity does not work with arrays.
+    // We have to use an ArrayList
+    private ArrayList<E> array; // The heap array
 
-	/**
-	 * Construct the binary heap.
-	 */
-	public BinaryHeap() {
-		this.currentSize = 0;
-		this.array = new ArrayList<E>() ;
-	}
+    /**
+     * Construct the binary heap.
+     */
+    public BinaryHeap() {
+        this.currentSize = 0;
+        this.array = new ArrayList<E>();
+    }
 
-	// Constructor used for debug.
-	public BinaryHeap(BinaryHeap<E> heap) {
-		this.currentSize = heap.currentSize ;
-		this.array = new ArrayList<E>(heap.array) ;
-	}
+    // Constructor used for debug.
+    public BinaryHeap(BinaryHeap<E> heap) {
+        this.currentSize = heap.currentSize;
+        this.array = new ArrayList<E>(heap.array);
+    }
 
-	// Sets an element in the array
-	private void arraySet(int index, E value) {
-		if (index == this.array.size()) {
-			this.array.add(value) ;
-		}
-		else {
-			this.array.set(index, value) ;
-		}
-	}
+    // Sets an element in the array
+    private void arraySet(int index, E value) {
+        if (index == this.array.size()) {
+            this.array.add(value);
+        }
+        else {
+            this.array.set(index, value);
+        }
+    }
 
-	/**
-	 * Test if the heap is logically empty.
-	 * @return true if empty, false otherwise.
-	 */
-	public boolean isEmpty() { return this.currentSize == 0; }
+    /**
+     * Test if the heap is logically empty.
+     * 
+     * @return true if empty, false otherwise.
+     */
+    public boolean isEmpty() {
+        return this.currentSize == 0;
+    }
 
-	/**
-	 * Returns size.
-	 * @return current size.
-	 */
-	public int size() { return this.currentSize; }
+    /**
+     * Returns size.
+     * 
+     * @return current size.
+     */
+    public int size() {
+        return this.currentSize;
+    }
 
+    /**
+     * Returns index of parent.
+     */
+    private int index_parent(int index) {
+        return (index - 1) / 2;
+    }
 
-	/**
-	 * Returns index of parent.
-	 */
-	private int index_parent(int index) {
-		return (index - 1) / 2 ;
-	}
+    /**
+     * Returns index of left child.
+     */
+    private int index_left(int index) {
+        return index * 2 + 1;
+    }
 
-	/**
-	 * Returns index of left child.
-	 */
-	private int index_left(int index) {
-		return index * 2 + 1 ;
-	}
+    /**
+     * Insert into the heap.
+     * 
+     * @param x the item to insert.
+     */
+    public void insert(E x) {
+        int index = this.currentSize++;
+        this.arraySet(index, x);
+        this.percolateUp(index);
+    }
 
-	/**
-	 * Insert into the heap.
-	 * @param x the item to insert.
-	 */
-	public void insert(E x) {
-		int index = this.currentSize++ ;
-		this.arraySet(index, x) ;
-		this.percolateUp(index) ;
-	}
+    /**
+     * Internal method to percolate up in the heap.
+     * 
+     * @param index the index at which the percolate begins.
+     */
+    private void percolateUp(int index) {
+        E x = this.array.get(index);
 
-	/**
-	 * Internal method to percolate up in the heap.
-	 * @param index the index at which the percolate begins.
-	 */
-	private void percolateUp(int index) {
-		E x = this.array.get(index) ;
+        for (; index > 0
+                && x.compareTo(this.array.get(index_parent(index))) < 0; index = index_parent(
+                        index)) {
+            E moving_val = this.array.get(index_parent(index));
+            this.arraySet(index, moving_val);
+        }
 
-		for( ; index > 0 && x.compareTo(this.array.get(index_parent(index)) ) < 0; index = index_parent(index) ) {
-			E moving_val = this.array.get(index_parent(index)) ;
-			this.arraySet(index, moving_val) ;
-		}
+        this.arraySet(index, x);
+    }
 
-		this.arraySet(index, x) ;
-	}
+    /**
+     * Internal method to percolate down in the heap.
+     * 
+     * @param index the index at which the percolate begins.
+     */
+    private void percolateDown(int index) {
+        int ileft = index_left(index);
+        int iright = ileft + 1;
 
-	/**
-	 * Internal method to percolate down in the heap.
-	 * @param index the index at which the percolate begins.
-	 */
-	private void percolateDown(int index) {
-		int ileft = index_left(index) ;
-		int iright = ileft + 1 ;
+        if (ileft < this.currentSize) {
+            E current = this.array.get(index);
+            E left = this.array.get(ileft);
+            boolean hasRight = iright < this.currentSize;
+            E right = (hasRight) ? this.array.get(iright) : null;
 
-		if (ileft < this.currentSize) {
-			E current = this.array.get(index) ;
-			E left = this.array.get(ileft) ;
-			boolean hasRight = iright < this.currentSize ;
-			E right = (hasRight)?this.array.get(iright):null ;
+            if (!hasRight || left.compareTo(right) < 0) {
+                // Left is smaller
+                if (left.compareTo(current) < 0) {
+                    this.arraySet(index, left);
+                    this.arraySet(ileft, current);
+                    this.percolateDown(ileft);
+                }
+            }
+            else {
+                // Right is smaller
+                if (right.compareTo(current) < 0) {
+                    this.arraySet(index, right);
+                    this.arraySet(iright, current);
+                    this.percolateDown(iright);
+                }
+            }
+        }
+    }
 
-			if (!hasRight || left.compareTo(right) < 0) {
-				// Left is smaller
-				if (left.compareTo(current) < 0) {
-					this.arraySet(index, left) ;
-					this.arraySet(ileft, current) ;
-					this.percolateDown( ileft ) ;
-				}
-			}
-			else {
-				// Right is smaller
-				if (right.compareTo(current) < 0) {
-					this.arraySet(index, right) ;
-					this.arraySet(iright, current) ;
-					this.percolateDown( iright ) ;
-				}		
-			}
-		}
-	}
+    /**
+     * Find the smallest item in the heap.
+     * 
+     * @return the smallest item in the heap.
+     * 
+     * @throws RuntimeException if this heap is empty.
+     */
+    public E findMin() throws RuntimeException {
+        if (isEmpty())
+            throw new RuntimeException("Empty binary heap");
+        return this.array.get(0);
+    }
 
-	/**
-	 * Find the smallest item in the heap.
-	 * @return the smallest item.
-	 * @throws Exception if empty.
-	 */
-	public E findMin( ) {
-		if( isEmpty() )
-			throw new RuntimeException( "Empty binary heap" );
-		return this.array.get(0);
-	}
+    /**
+     * Remove the smallest item from the heap.
+     * 
+     * @return the smallest item in the heap.
+     * 
+     * @throws RuntimeException if this heap is empty.
+     */
+    public E deleteMin() throws RuntimeException {
+        E minItem = findMin();
+        E lastItem = this.array.get(--this.currentSize);
+        this.arraySet(0, lastItem);
+        this.percolateDown(0);
+        return minItem;
+    }
 
-	/**
-	 * Remove the smallest item from the heap.
-	 * @return the smallest item.
-	 * @throws Exception if empty.
-	 */
-	public E deleteMin( ) {
-		E minItem = findMin( );
-		E lastItem = this.array.get(--this.currentSize) ;
-		this.arraySet(0, lastItem) ;
-		this.percolateDown( 0 );
-		return minItem;
-	}
+    /**
+     * Prints the heap
+     */
+    public void print() {
+        System.out.println();
+        System.out.println("========  HEAP  (size = " + this.currentSize + ")  ========");
+        System.out.println();
 
-	/**
-	 * Prints the heap
-	 */
-	public void print() {
-		System.out.println() ;
-		System.out.println("========  HEAP  (size = " + this.currentSize + ")  ========") ;
-		System.out.println() ;
+        for (int i = 0; i < this.currentSize; i++) {
+            System.out.println(this.array.get(i).toString());
+        }
 
-		for (int i = 0 ; i < this.currentSize ; i++) {
-			System.out.println(this.array.get(i).toString()) ;
-		}
+        System.out.println();
+        System.out.println("--------  End of heap  --------");
+        System.out.println();
+    }
 
-		System.out.println() ;
-		System.out.println("--------  End of heap  --------") ;
-		System.out.println() ;
-	}
+    /**
+     * Prints the elements of the heap according to their respective order.
+     */
+    public void printSorted() {
 
-	/**
-	 * Prints the elements of the heap according to their respective order.
-	 */
-	public void printSorted() {
+        BinaryHeap<E> copy = new BinaryHeap<E>(this);
 
-		BinaryHeap<E> copy = new BinaryHeap<E>(this) ;
+        System.out.println();
+        System.out.println("========  Sorted HEAP  (size = " + this.currentSize + ")  ========");
+        System.out.println();
 
-		System.out.println() ;
-		System.out.println("========  Sorted HEAP  (size = " + this.currentSize + ")  ========") ;
-		System.out.println() ;
+        while (!copy.isEmpty()) {
+            System.out.println(copy.deleteMin());
+        }
 
-		while (!copy.isEmpty()) {
-			System.out.println(copy.deleteMin()) ;
-		}
+        System.out.println();
+        System.out.println("--------  End of heap  --------");
+        System.out.println();
+    }
 
-		System.out.println() ;
-		System.out.println("--------  End of heap  --------") ;
-		System.out.println() ;
-	}
-
-
-
-	// Test program : compare with the reference implementation PriorityQueue.
-	public static void main(String [] args) {
-		BinaryHeap<Integer> heap = new BinaryHeap<Integer>() ;
-		PriorityQueue<Integer> queue = new PriorityQueue<Integer>() ;
-
-		int count = 0 ;
-		int blocksize = 10000 ;
-
-		System.out.println("Interrupt to stop the test.") ;
-
-		while (true) {
-
-			// Insert up to blocksize elements
-			int nb_insert = (int)(Math.random() * (blocksize + 1)) ;
-
-			for (int i = 0 ; i < nb_insert ; i++) {
-				Integer obj = new Integer(i) ;
-				heap.insert(obj) ;
-				queue.add(obj) ;
-			}
-
-			// Remove up to blocksize elements
-			int nb_remove = (int)(Math.random() * blocksize * 1.1) ;
-
-			if (nb_remove > queue.size()) {
-				nb_remove = queue.size() ;
-			}
-
-			for (int i = 0 ; i < nb_remove ; i++) {
-
-				int removed1 = queue.poll().intValue() ;
-				int removed2 = heap.deleteMin().intValue() ;
-
-				if (removed1 != removed2) {
-					System.out.println("Ouch : expected " + removed1 + "  .. but got " + removed2) ;
-					System.exit(1) ;
-				}
-			}
-
-			if (heap.size() != queue.size()) {
-				System.out.println("Ouch : heap size = " + heap.size() + "  queue size = " + queue.size() ) ;
-				System.exit(1) ;
-			}
-
-			count += nb_remove ;
-
-			if (count > 1000000) {
-				System.out.println("" + count + " items successfully compared. Heap size : " + heap.size()) ;
-				count = 0 ;
-			}
-		}
-	}
 }
diff --git a/src/main/org/insa/algo/strongconnectivity/StronglyConnectedComponentObserver.java b/src/main/org/insa/algo/strongconnectivity/StronglyConnectedComponentObserver.java
deleted file mode 100644
index 69f1a01..0000000
--- a/src/main/org/insa/algo/strongconnectivity/StronglyConnectedComponentObserver.java
+++ /dev/null
@@ -1,30 +0,0 @@
-package org.insa.algo.strongconnectivity;
-
-import java.util.ArrayList;
-
-import org.insa.graph.Node;
-
-public interface StronglyConnectedComponentObserver {
-
-	/**
-	 * Notify that the algorithm is entering a new component.
-	 * 
-	 * @param curNode Starting node for the component.
-	 */
-	public void notifyStartComponent(Node curNode);
-	
-	/**
-	 * Notify that a new node has been found for the current component.
-	 * 
-	 * @param node New node found for the current component.
-	 */
-	public void notifyNewNodeInComponent(Node node);
-	
-	/**
-	 * Notify that the algorithm has computed a new component.
-	 * 
-	 * @param nodes List of nodes in the component.
-	 */
-	public void notifyEndComponent(ArrayList<Node> nodes);
-
-}
diff --git a/src/main/org/insa/algo/strongconnectivity/StronglyConnectedComponentsAlgorithm.java b/src/main/org/insa/algo/strongconnectivity/StronglyConnectedComponentsAlgorithm.java
deleted file mode 100644
index 2ddfcd1..0000000
--- a/src/main/org/insa/algo/strongconnectivity/StronglyConnectedComponentsAlgorithm.java
+++ /dev/null
@@ -1,25 +0,0 @@
-package org.insa.algo.strongconnectivity;
-
-import org.insa.algo.AbstractAlgorithm;
-
-public abstract class StronglyConnectedComponentsAlgorithm
-        extends AbstractAlgorithm<StronglyConnectedComponentObserver> {
-
-    /**
-     * @param data
-     */
-    public StronglyConnectedComponentsAlgorithm(StronglyConnectedComponentsData data) {
-        super(data);
-    }
-
-    @Override
-    public StronglyConnectedComponentsSolution run() {
-        return (StronglyConnectedComponentsSolution) super.run();
-    }
-
-    @Override
-    public StronglyConnectedComponentsData getInputData() {
-        return (StronglyConnectedComponentsData) super.getInputData();
-    }
-
-}
diff --git a/src/main/org/insa/algo/strongconnectivity/StronglyConnectedComponentsData.java b/src/main/org/insa/algo/strongconnectivity/StronglyConnectedComponentsData.java
deleted file mode 100644
index a42ab71..0000000
--- a/src/main/org/insa/algo/strongconnectivity/StronglyConnectedComponentsData.java
+++ /dev/null
@@ -1,16 +0,0 @@
-package org.insa.algo.strongconnectivity;
-
-import org.insa.algo.AbstractInputData;
-import org.insa.graph.Graph;
-
-public class StronglyConnectedComponentsData extends AbstractInputData {
-
-    /**
-     * 
-     * @param graph
-     */
-    public StronglyConnectedComponentsData(Graph graph) {
-        super(graph);
-    }
-
-}
diff --git a/src/main/org/insa/algo/strongconnectivity/StronglyConnectedComponentsSolution.java b/src/main/org/insa/algo/strongconnectivity/StronglyConnectedComponentsSolution.java
deleted file mode 100644
index cde68f2..0000000
--- a/src/main/org/insa/algo/strongconnectivity/StronglyConnectedComponentsSolution.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package org.insa.algo.strongconnectivity;
-
-import java.util.ArrayList;
-
-import org.insa.algo.AbstractSolution;
-import org.insa.graph.Node;
-
-public class StronglyConnectedComponentsSolution extends AbstractSolution {
-
-    // Components
-    private ArrayList<ArrayList<Node>> components;
-
-    protected StronglyConnectedComponentsSolution(StronglyConnectedComponentsData data) {
-        super(data);
-    }
-
-    protected StronglyConnectedComponentsSolution(StronglyConnectedComponentsData data,
-            Status status, ArrayList<ArrayList<Node>> components) {
-        super(data, status);
-        this.components = components;
-    }
-
-    @Override
-    public StronglyConnectedComponentsData getInputData() {
-        return (StronglyConnectedComponentsData) super.getInputData();
-    }
-
-    /**
-     * @return Components of the solution, if any.
-     */
-    public ArrayList<ArrayList<Node>> getComponents() {
-        return components;
-    }
-
-}
diff --git a/src/main/org/insa/algo/strongconnectivity/TarjanAlgorithm.java b/src/main/org/insa/algo/strongconnectivity/TarjanAlgorithm.java
deleted file mode 100644
index fc2363b..0000000
--- a/src/main/org/insa/algo/strongconnectivity/TarjanAlgorithm.java
+++ /dev/null
@@ -1,144 +0,0 @@
-package org.insa.algo.strongconnectivity;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Stack;
-
-import org.insa.algo.AbstractSolution.Status;
-import org.insa.graph.Arc;
-import org.insa.graph.Graph;
-import org.insa.graph.Node;
-
-public class TarjanAlgorithm extends StronglyConnectedComponentsAlgorithm {
-
-    private final static int UNDEFINED = -1;
-
-    // Stack of nodes and flags.
-    private Stack<Node> stack;
-    private boolean[] inStack;
-
-    // Current index.
-    private int index;
-
-    // Information of nodes
-    private int[] indexes;
-    private int[] lowlink;
-
-    // Array of strongly connected components
-    ArrayList<ArrayList<Node>> components;
-
-    public TarjanAlgorithm(StronglyConnectedComponentsData data) {
-        super(data);
-    }
-
-    /**
-     * Push the given node to the stack.
-     * 
-     * @param node
-     */
-    protected void pushNode(Node node) {
-        stack.push(node);
-        inStack[node.getId()] = true;
-    }
-
-    /**
-     * Pop and return a node from the stack.
-     * 
-     * @return Node popped from the stack
-     */
-    protected Node popNode() {
-        Node top = stack.pop();
-        inStack[top.getId()] = false;
-        return top;
-    }
-
-    /**
-     * Check if the given node is in the stack.
-     * 
-     * @param node
-     * 
-     * @return true if the given node is in the stack, false otherwize.
-     */
-    protected boolean isInStack(Node node) {
-        return inStack[node.getId()];
-    }
-
-    /**
-     * Find the strong component containing the given node.
-     * 
-     * @param node
-     * 
-     * @return The strong component containing the given node.
-     */
-    protected void findAndAddStrongComponent(Node v) {
-
-        // Update node info, index and push the node.
-        indexes[v.getId()] = index;
-        lowlink[v.getId()] = index;
-        index += 1;
-        pushNode(v);
-
-        for (Arc a: v.getSuccessors()) {
-            Node w = a.getDestination();
-            if (!hasBeenVisited(w)) {
-                findAndAddStrongComponent(w);
-                lowlink[v.getId()] = Math.min(lowlink[v.getId()], lowlink[w.getId()]);
-            }
-            else if (isInStack(w)) {
-                lowlink[v.getId()] = Math.min(lowlink[v.getId()], indexes[w.getId()]);
-            }
-        }
-
-        // Compute the component (if any)
-        if (lowlink[v.getId()] == indexes[v.getId()]) {
-            ArrayList<Node> component = new ArrayList<Node>();
-            Node w;
-            do {
-                w = popNode();
-                component.add(w);
-            } while (!w.equals(v));
-            components.add(component);
-            System.out.println("Size of the stack: " + stack.size());
-        }
-
-    }
-
-    /**
-     * Check if the given node has not been visited yet.
-     * 
-     * @return true if the node has been visited.
-     */
-    protected boolean hasBeenVisited(Node node) {
-        return this.indexes[node.getId()] != UNDEFINED;
-    }
-
-    @Override
-    protected StronglyConnectedComponentsSolution doRun() {
-        Graph graph = getInputData().getGraph();
-
-        components = new ArrayList<ArrayList<Node>>();
-
-        // Initialize everything
-        final int nbNodes = graph.getNodes().size();
-        stack = new Stack<Node>();
-        inStack = new boolean[nbNodes];
-
-        // Current index.
-        index = 0;
-
-        // Information of nodes
-        indexes = new int[nbNodes];
-        Arrays.fill(indexes, UNDEFINED);
-        lowlink = new int[nbNodes];
-
-        // Find components
-        for (Node node: graph.getNodes()) {
-            if (!hasBeenVisited(node)) {
-                findAndAddStrongComponent(node);
-            }
-        }
-
-        return new StronglyConnectedComponentsSolution(getInputData(), Status.OPTIMAL, components);
-    }
-
-}
diff --git a/src/main/org/insa/graph/Arc.java b/src/main/org/insa/graph/Arc.java
index bc4f283..2f5b3d8 100644
--- a/src/main/org/insa/graph/Arc.java
+++ b/src/main/org/insa/graph/Arc.java
@@ -8,7 +8,7 @@ import java.util.List;
  * (without having to duplicate attributes).
  * 
  * Arc should never be created manually but always using the
- * {@link Node#linkNodes(Node, Node, int, RoadInformation, java.util.ArrayList)}
+ * {@link Node#linkNodes(Node, Node, float, RoadInformation, java.util.ArrayList)}
  * method to ensure proper instantiation of the {@link ArcForward} and
  * {@link ArcBackward} classes.
  * 
diff --git a/src/main/org/insa/graph/GraphStatistics.java b/src/main/org/insa/graph/GraphStatistics.java
index a6c24ef..db575b5 100644
--- a/src/main/org/insa/graph/GraphStatistics.java
+++ b/src/main/org/insa/graph/GraphStatistics.java
@@ -10,6 +10,12 @@ package org.insa.graph;
  */
 public class GraphStatistics {
 
+    /**
+     * Special value used to indicate that the graph has no maximum speed limit
+     * (some roads are not limited).
+     */
+    public static final int NO_MAXIMUM_SPEED = -1;
+
     /**
      * Class representing a bounding box for a graph (a rectangle that contains all
      * nodes in the graph).
@@ -59,8 +65,10 @@ public class GraphStatistics {
     /**
      * Create a new GraphStatistics instance with the given value.
      * 
-     * @param maximumSpeed Maximum speed of any road of the graph. A value of 0 may
-     *        be used to indicate that this graph has no maximum limitation.
+     * @param boundingBox Bounding-box for 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) {
@@ -77,8 +85,15 @@ public class GraphStatistics {
     }
 
     /**
-     * @return Maximum speed of any arc in the graph, or 0 if some road have no
-     *         speed limitations.
+     * @return true if this graph has a maximum speed limit, false otherwise.
+     */
+    public boolean hasMaximumSpeed() {
+        return this.maximumLength != NO_MAXIMUM_SPEED;
+    }
+
+    /**
+     * @return Maximum speed of any arc in the graph, or {@link #NO_MAXIMUM_SPEED}
+     *         if some roads have no speed limitation.
      */
     public int getMaximumSpeed() {
         return this.maximumSpeed;
diff --git a/src/main/org/insa/graphics/drawing/BasicGraphPalette.java b/src/main/org/insa/graphics/drawing/BasicGraphPalette.java
index bce9674..bca569f 100644
--- a/src/main/org/insa/graphics/drawing/BasicGraphPalette.java
+++ b/src/main/org/insa/graphics/drawing/BasicGraphPalette.java
@@ -8,19 +8,10 @@ import org.insa.graph.RoadInformation.RoadType;
 public class BasicGraphPalette implements GraphPalette {
 
     // Color types for arc.
-    static final Color motorway = Color.RED;
-    static final Color bigroad = new Color(255, 105, 0);
-    static final Color smallroad = new Color(255, 234, 0);
-    static final Color coastline = Color.BLUE;
-
-    // Default point width
-    static final int DEFAULT_POINT_WIDTH = 1;
-
-    /**
-     * 
-     */
-    public BasicGraphPalette() {
-    }
+    private static final Color MOTORWAY_COLOR = Color.RED;
+    private static final Color BIG_ROAD_COLOR = new Color(255, 105, 0);
+    private static final Color SMALL_ROAD_COLOR = new Color(255, 234, 0);
+    private static final Color COASTLINE_COLOR = Color.BLUE;
 
     @Override
     public int getDefaultPointWidth() {
@@ -35,19 +26,16 @@ public class BasicGraphPalette implements GraphPalette {
     @Override
     public Color getColorForArc(Arc arc) {
         RoadType type = arc.getRoadInformation().getType();
-        Color color = Color.BLACK;
         switch (type) {
         case MOTORWAY:
-            color = motorway;
-            break;
+            return MOTORWAY_COLOR;
         case TRUNK:
         case PRIMARY:
         case SECONDARY:
         case MOTORWAY_LINK:
         case TRUNK_LINK:
         case PRIMARY_LINK:
-            color = bigroad;
-            break;
+            return BIG_ROAD_COLOR;
         case SECONDARY_LINK:
         case TERTIARY:
         case RESIDENTIAL:
@@ -58,14 +46,12 @@ public class BasicGraphPalette implements GraphPalette {
         case PEDESTRIAN:
         case CYCLEWAY:
         case TRACK:
-            color = smallroad;
-            break;
+            return SMALL_ROAD_COLOR;
         case COASTLINE:
-            color = coastline;
-            break;
+            return COASTLINE_COLOR;
         }
 
-        return color;
+        return Color.BLACK;
     }
 
     @Override
diff --git a/src/main/org/insa/graphics/drawing/Drawing.java b/src/main/org/insa/graphics/drawing/Drawing.java
index 4a456d8..5cf48c2 100644
--- a/src/main/org/insa/graphics/drawing/Drawing.java
+++ b/src/main/org/insa/graphics/drawing/Drawing.java
@@ -14,31 +14,34 @@ public interface Drawing {
     /**
      * Add a listener to click to this drawing.
      * 
-     * @param listener
+     * @param listener DrawingClickListener to add to this Drawing.
      */
     public void addDrawingClickListener(DrawingClickListener listener);
 
     /**
      * Remove the given listener from the drawing.
      * 
-     * @param listener
+     * @param listener DrawingClickListener to remove from this Drawing.
      */
     public void removeDrawingClickListener(DrawingClickListener listener);
 
     /**
-     * Clear the drawing.
+     * Clear the drawing (overlays and underlying graph/map).
      */
     public void clear();
 
     /**
-     * Remove overlays from the drawing.
+     * Remove overlays from the drawing (do not remove the underlying graph/map).
      */
     public void clearOverlays();
 
     /**
-     * Draw the given point with the given color.
+     * Draw a marker at the given position with the given color.
      * 
-     * @param point
+     * @param point Position of the marker to draw.
+     * @param color Color of the marker to draw.
+     * 
+     * @return A MarkerOverlay instance representing the newly drawn marker.
      */
     public MarkerOverlay drawMarker(Point point, Color color);
 
@@ -48,65 +51,86 @@ public interface Drawing {
      * 
      * PointSetOverlay are heavy memory resources, do not use one for each point!
      * 
+     * @return A new PointSetOverlay for this drawing.
      */
     public PointSetOverlay createPointSetOverlay();
 
     /**
-     * Create a new PointSetOverlay with the original width and color that can be
-     * used to add overlay points to this drawing.
+     * Create a new PointSetOverlay with the given initial width and color that can
+     * be used to add overlay points to this drawing.
      * 
      * PointSetOverlay are heavy memory resources, do not use one for each point!
      * 
+     * @param width Initial width of points in the overlay.
+     * @param color Initial width of points in the overlay.
+     * 
+     * @return A new PointSetOverlay for this drawing.
      */
     public PointSetOverlay createPointSetOverlay(int width, Color color);
 
     /**
      * Draw the given graph using the given palette.
      * 
-     * @param graph
-     * @param palette
+     * @param graph Graph to draw.
+     * @param palette Palette to use to draw the graph.
+     * 
+     * @see BasicGraphPalette
+     * @see BlackAndWhiteGraphPalette
      */
     public void drawGraph(Graph graph, GraphPalette palette);
 
     /**
      * Draw the given graph using a default palette specific to the implementation.
      * 
-     * @param graph
+     * @param graph Graph to draw.
      */
     public void drawGraph(Graph graph);
 
     /**
      * Draw a path using the given color.
      * 
-     * @param path
-     * @param color
-     * @param markers Show origin and destination markers.
-     * @return
+     * @param path Path to draw.
+     * @param color Color of the path to draw.
+     * @param markers true to show origin and destination markers.
+     * 
+     * @return A PathOverlay instance representing the newly drawn path.
      */
     public PathOverlay drawPath(Path path, Color color, boolean markers);
 
     /**
-     * Draw a path using the given color with markers.
+     * Draw a path with both origin and destination markers using the given color.
      * 
-     * @param path
-     * @param color
+     * @param path Path to draw.
+     * @param color Color of the path to draw.
+     * 
+     * @return A PathOverlay instance representing the newly drawn path.
+     * 
+     * @see Drawing#drawPath(Path, Color, boolean)
      */
     public PathOverlay drawPath(Path path, Color color);
 
     /**
      * Draw a path using a default color specific to the implementation
      * 
+     * @param path Path to draw.
+     * @param markers true to show origin and destination markers.
      * 
-     * @param path
-     * @param markers Show origin and destination markers.
+     * @return A PathOverlay instance representing the newly drawn path.
+     * 
+     * @see Drawing#drawPath(Path, Color, boolean)
      */
     public PathOverlay drawPath(Path path, boolean markers);
 
     /**
-     * Draw a path using a default color specific to the implementation
+     * Draw a path with both origin and destination markers using a default color
+     * specific to the implementation
      * 
      * 
-     * @param path
+     * @param path Path to draw.
+     * 
+     * @return A PathOverlay instance representing the newly drawn path.
+     * 
+     * @see Drawing#drawPath(Path, Color, boolean)
      */
     public PathOverlay drawPath(Path path);
 
diff --git a/src/main/org/insa/graphics/drawing/DrawingClickListener.java b/src/main/org/insa/graphics/drawing/DrawingClickListener.java
index 2e2203c..496d841 100644
--- a/src/main/org/insa/graphics/drawing/DrawingClickListener.java
+++ b/src/main/org/insa/graphics/drawing/DrawingClickListener.java
@@ -7,7 +7,7 @@ public interface DrawingClickListener {
     /**
      * Event triggered when a click is made on the map.
      * 
-     * @param point
+     * @param point Position (on the map) of the mouse click.
      */
     public void mouseClicked(Point point);
 
diff --git a/src/main/org/insa/graphics/drawing/GraphPalette.java b/src/main/org/insa/graphics/drawing/GraphPalette.java
index 4ba62a3..b4292e4 100644
--- a/src/main/org/insa/graphics/drawing/GraphPalette.java
+++ b/src/main/org/insa/graphics/drawing/GraphPalette.java
@@ -17,14 +17,14 @@ public interface GraphPalette {
     public Color getDefaultPointColor();
 
     /**
-     * @param arc
+     * @param arc Arc for which color should be retrieved.
      * 
      * @return Color associated with the given arc.
      */
     public Color getColorForArc(Arc arc);
 
     /**
-     * @param arc
+     * @param arc Arc for which width should be retrieved.
      * 
      * @return Width associated with the given arc.
      */
diff --git a/src/main/org/insa/graphics/drawing/components/BasicDrawing.java b/src/main/org/insa/graphics/drawing/components/BasicDrawing.java
index 46495c0..ea1f297 100644
--- a/src/main/org/insa/graphics/drawing/components/BasicDrawing.java
+++ b/src/main/org/insa/graphics/drawing/components/BasicDrawing.java
@@ -449,11 +449,15 @@ public class BasicDrawing extends JPanel implements Drawing {
      * Return the longitude and latitude corresponding to the given position of the
      * MouseEvent.
      * 
-     * @param event
+     * @param event MouseEvent from which longitude/latitude should be retrieved.
      * 
-     * @return
+     * @return Point representing the projection of the MouseEvent position in the
+     *         graph/map.
+     * 
+     * @throws NoninvertibleTransformException if the actual transformation is
+     *         invalid.
      */
-    public Point getLongitudeLatitude(MouseEvent event) throws NoninvertibleTransformException {
+    protected Point getLongitudeLatitude(MouseEvent event) throws NoninvertibleTransformException {
         // Get the point using the inverse transform of the Zoom/Pan object, this gives
         // us
         // a point within the drawing box (between [0, 0] and [width, height]).
diff --git a/src/main/org/insa/graphics/drawing/components/MapZoomControls.java b/src/main/org/insa/graphics/drawing/components/MapZoomControls.java
index dcd4f82..8785eea 100644
--- a/src/main/org/insa/graphics/drawing/components/MapZoomControls.java
+++ b/src/main/org/insa/graphics/drawing/components/MapZoomControls.java
@@ -111,7 +111,7 @@ public class MapZoomControls {
     /**
      * Add a zoom-in listener.
      * 
-     * @param listener
+     * @param listener Zoom-in listener to add to this MapZoomControls instance.
      */
     public void addZoomInListener(ActionListener listener) {
         this.zoomInListeners.add(listener);
@@ -120,7 +120,7 @@ public class MapZoomControls {
     /**
      * Add a zoom-out listener.
      * 
-     * @param listener
+     * @param listener Zoom-out listener to add to this MapZoomControls instance.
      */
     public void addZoomOutListener(ActionListener listener) {
         this.zoomOutListeners.add(listener);
@@ -134,9 +134,9 @@ public class MapZoomControls {
     }
 
     /**
-     * Set the current zoom level.
+     * Set the current zoom level without requesting a redraw.
      * 
-     * @param level
+     * @param level Zoom level to set.
      */
     public void setZoomLevel(int level) {
         this.currentLevel = level;
@@ -161,10 +161,10 @@ public class MapZoomControls {
      * Check if a point is contained inside an element of this zoom controls, useful
      * to avoid spurious click listeners.
      * 
-     * @param point
+     * @param point Point to check.
      * 
      * @return true if the given point correspond to an element of this zoom
-     * controls.
+     *         controls.
      */
     public boolean contains(Point point) {
         return zoomInRect.contains(point) || zoomOutRect.contains(point);
diff --git a/src/main/org/insa/graphics/drawing/overlays/MarkerAutoScaling.java b/src/main/org/insa/graphics/drawing/overlays/MarkerAutoScaling.java
index 70e1435..8c6f0a3 100644
--- a/src/main/org/insa/graphics/drawing/overlays/MarkerAutoScaling.java
+++ b/src/main/org/insa/graphics/drawing/overlays/MarkerAutoScaling.java
@@ -11,11 +11,27 @@ import org.mapsforge.core.model.Point;
 import org.mapsforge.map.awt.graphics.AwtBitmap;
 import org.mapsforge.map.layer.overlay.Marker;
 
+/**
+ * Class extending the default Mapsforge's {@link Marker} with auto-scaling.
+ * 
+ * Mapsforge's Markers do not scale with zoom level, this class aims at
+ * correcting this. Internally, this image stores an {@link Image} instance and
+ * scale it when a redraw is requested.
+ * 
+ * @see MarkerUtils#getMarkerForColor(java.awt.Color)
+ * @see PaintUtils#getStrokeWidth(int, byte)
+ */
 public class MarkerAutoScaling extends Marker {
 
     // Original image.
     private Image image;
 
+    /**
+     * Create a new MarkerAutoScaling at the given position with the given image.
+     * 
+     * @param latLong Initial position of the marker.
+     * @param image Image for this marker.
+     */
     public MarkerAutoScaling(LatLong latLong, Image image) {
         super(latLong, null, 0, 0);
         this.image = image;
diff --git a/src/main/org/insa/graphics/drawing/overlays/MarkerOverlay.java b/src/main/org/insa/graphics/drawing/overlays/MarkerOverlay.java
index a761af9..23baf29 100644
--- a/src/main/org/insa/graphics/drawing/overlays/MarkerOverlay.java
+++ b/src/main/org/insa/graphics/drawing/overlays/MarkerOverlay.java
@@ -5,12 +5,14 @@ import org.insa.graph.Point;
 public interface MarkerOverlay extends Overlay {
 
     /**
-     * @return The point associated with this marker.
+     * @return The current position of this marker.
      */
     public Point getPoint();
 
     /**
+     * Move this marker to the specified location.
      * 
+     * @param point New position for the marker.
      */
     public void moveTo(Point point);
 
diff --git a/src/main/org/insa/graphics/drawing/overlays/MarkerUtils.java b/src/main/org/insa/graphics/drawing/overlays/MarkerUtils.java
index c4d045f..0908c92 100644
--- a/src/main/org/insa/graphics/drawing/overlays/MarkerUtils.java
+++ b/src/main/org/insa/graphics/drawing/overlays/MarkerUtils.java
@@ -11,15 +11,17 @@ public class MarkerUtils {
     private static final String MARKER_MASK_FILE = "res/marker_mask.bin";
 
     /**
-     * Create a Bitmap representing a marker of the given color.
+     * Create an Image representing a marker of the given color.
      * 
-     * @param color
-     * @return
+     * @param color Color of the marker.
+     * 
+     * @return A new Image representing a marker with the given color.
      */
     public static Image getMarkerForColor(Color color) {
         // create image
         int[][] mask = readMarkerMask();
-        BufferedImage image = new BufferedImage(mask[0].length, mask.length, BufferedImage.TYPE_4BYTE_ABGR);
+        BufferedImage image = new BufferedImage(mask[0].length, mask.length,
+                BufferedImage.TYPE_4BYTE_ABGR);
 
         // Color[] map = getColorMapping(color);
         int rgb = color.getRGB() & 0x00ffffff;
diff --git a/src/main/org/insa/graphics/drawing/overlays/PaintUtils.java b/src/main/org/insa/graphics/drawing/overlays/PaintUtils.java
index a4eae00..59413ed 100644
--- a/src/main/org/insa/graphics/drawing/overlays/PaintUtils.java
+++ b/src/main/org/insa/graphics/drawing/overlays/PaintUtils.java
@@ -4,6 +4,8 @@ import java.awt.Color;
 
 import org.mapsforge.core.graphics.GraphicFactory;
 import org.mapsforge.map.awt.graphics.AwtGraphicFactory;
+import org.mapsforge.map.layer.overlay.Marker;
+import org.mapsforge.map.layer.overlay.Polyline;
 
 public class PaintUtils {
 
@@ -13,8 +15,9 @@ public class PaintUtils {
     /**
      * Convert the given AWT color to a mapsforge compatible color.
      * 
-     * @param color
-     * @return
+     * @param color AWT color to convert.
+     * 
+     * @return Integer value representing a corresponding mapsforge color.
      */
     public static int convertColor(Color color) {
         return GRAPHIC_FACTORY.createColor(color.getAlpha(), color.getRed(), color.getGreen(),
@@ -24,16 +27,23 @@ public class PaintUtils {
     /**
      * Convert the given mapsforge color to an AWT Color.
      * 
-     * @param color
-     * @return
+     * @param color Integer value representing a mapsforge color.
+     * 
+     * @return AWT color corresponding to the given value.
      */
     public static Color convertColor(int color) {
         return new Color(color, true);
     }
 
     /**
-     * @param width
-     * @return
+     * Compute an updated value for the given width at the given zoom level. This
+     * function can be used to automatically scale {@link Polyline} or
+     * {@link Marker} when zooming (which is not done by default in Mapsforge).
+     * 
+     * @param width Original width to convert.
+     * @param zoomLevel Zoom level for which the width should be computed.
+     * 
+     * @return Actual width at the given zoom level.
      */
     public static float getStrokeWidth(int width, byte zoomLevel) {
         float mul = 1;
diff --git a/src/main/org/insa/graphics/drawing/overlays/PointSetOverlay.java b/src/main/org/insa/graphics/drawing/overlays/PointSetOverlay.java
index c294972..fbae987 100644
--- a/src/main/org/insa/graphics/drawing/overlays/PointSetOverlay.java
+++ b/src/main/org/insa/graphics/drawing/overlays/PointSetOverlay.java
@@ -9,48 +9,61 @@ public interface PointSetOverlay extends Overlay {
     /**
      * Set the width of this overlay for future addPoint().
      * 
-     * @param width
+     * @param width New default width for this overlay.
      */
     public void setWidth(int width);
 
     /**
      * Set color and width for this overlay for future addPoint().
      * 
-     * @param width
-     * @param color
+     * @param width New default width for this overlay.
+     * @param color New default color for this overlay.
      */
     public void setWidthAndColor(int width, Color color);
 
     /**
      * Add a new point using the current width and color.
      * 
-     * @param point
+     * @param point Position of the point to add.
+     * 
+     * @see #setWidth(int)
+     * @see #setColor(Color)
      */
     public void addPoint(Point point);
 
     /**
      * Set the current width and then add a new point.
      * 
-     * @param point
-     * @param width
+     * @param point Position of the point to add.
+     * @param width New default width for this overlay.
+     * 
+     * @see #setWidth(int)
+     * @see PointSetOverlay#addPoint(Point)
      */
     public void addPoint(Point point, int width);
 
     /**
      * Set the current color and then add a new point.
      * 
-     * @param point
-     * @param color
+     * @param point Position of the point to add.
+     * @param color New default color for this overlay.
+     * 
+     * @see #setColor(Color)
+     * @see PointSetOverlay#addPoint(Point)
      */
     public void addPoint(Point point, Color color);
 
     /**
-     * Add a new point to this set at the given location, with the given color and
-     * width, and update the current color.
+     * Add a new point at the given location, with the given color and width, and
+     * update the current width and color.
      * 
-     * @param point
-     * @param width
-     * @param color
+     * @param point Position of the point to add.
+     * @param width New default width for this overlay.
+     * @param color New default color for this overlay.
+     * 
+     * @see #setWidth(int)
+     * @see #setColor(Color)
+     * @see PointSetOverlay#addPoint(Point)
      */
     public void addPoint(Point point, int width, Color color);
 
diff --git a/src/main/org/insa/graphics/drawing/overlays/PolylineAutoScaling.java b/src/main/org/insa/graphics/drawing/overlays/PolylineAutoScaling.java
index e0b2f24..beb344e 100644
--- a/src/main/org/insa/graphics/drawing/overlays/PolylineAutoScaling.java
+++ b/src/main/org/insa/graphics/drawing/overlays/PolylineAutoScaling.java
@@ -12,6 +12,15 @@ import org.mapsforge.core.model.LatLong;
 import org.mapsforge.map.awt.graphics.AwtGraphicFactory;
 import org.mapsforge.map.layer.overlay.Polyline;
 
+/**
+ * Class extending the default Mapsforge's {@link Polyline} with auto-scaling.
+ * 
+ * Mapsforge's Polylines do not scale with zoom level, this class aims at
+ * correcting this. When a redraw is requested, the width of the line is
+ * recomputed for the current zoom level.
+ * 
+ * @see PaintUtils#getStrokeWidth(int, byte)
+ */
 public class PolylineAutoScaling extends Polyline {
 
     // Graphic factory.
@@ -21,8 +30,12 @@ public class PolylineAutoScaling extends Polyline {
     private final int width;
 
     /**
-     * @param width
-     * @param color
+     * Create a new PolylineAutoScaling with the given width and color.
+     * 
+     * @param width Original width of the line (independent of the zoom level).
+     * @param color Color of the line.
+     * 
+     * @see PaintUtils#getStrokeWidth(int, byte)
      */
     public PolylineAutoScaling(int width, Color color) {
         super(GRAPHIC_FACTORY.createPaint(), GRAPHIC_FACTORY);
@@ -48,14 +61,14 @@ public class PolylineAutoScaling extends Polyline {
     }
 
     /**
-     * @param point
+     * @param point Point to add to this line.
      */
     public void add(Point point) {
         getLatLongs().add(new LatLong(point.getLatitude(), point.getLongitude()));
     }
 
     /**
-     * @param points
+     * @param points Points to add to this line.
      */
     public void add(List<Point> points) {
         for (Point point: points) {