diff --git a/src/main/org/insa/graph/io/AbstractGraphReader.java b/src/main/org/insa/graph/io/AbstractGraphReader.java
index 5fc4b6f..a1067f6 100644
--- a/src/main/org/insa/graph/io/AbstractGraphReader.java
+++ b/src/main/org/insa/graph/io/AbstractGraphReader.java
@@ -1,16 +1,18 @@
 package org.insa.graph.io;
 
+import java.io.IOException;
+
 import org.insa.graph.Graph;
 
 public interface AbstractGraphReader {
-	
-	/**
-	 * Read a graph an returns it.
-	 * 
-	 * @return Graph.
-	 * @throws Exception 
-	 * 
-	 */
-	public Graph read() throws Exception;
+
+    /**
+     * Read a graph an returns it.
+     * 
+     * @return Graph.
+     * @throws Exception
+     * 
+     */
+    public Graph read() throws IOException;
 
 }
diff --git a/src/main/org/insa/graph/io/AbstractPathReader.java b/src/main/org/insa/graph/io/AbstractPathReader.java
index 296e5d4..53feab3 100644
--- a/src/main/org/insa/graph/io/AbstractPathReader.java
+++ b/src/main/org/insa/graph/io/AbstractPathReader.java
@@ -1,18 +1,20 @@
 package org.insa.graph.io;
 
+import java.io.IOException;
+
 import org.insa.graph.Graph;
 import org.insa.graph.Path;
 
 public interface AbstractPathReader {
 
-	/**
-	 * Read a path of the given graph and returns it.
-	 * 
-	 * @param graph Graph of the path.
-	 * 
-	 * @return A new path.
-	 * @throws Exception 
-	 */
-	public Path readPath(Graph graph) throws Exception;
-	
+    /**
+     * Read a path of the given graph and returns it.
+     * 
+     * @param graph Graph of the path.
+     * 
+     * @return A new path.
+     * @throws Exception
+     */
+    public Path readPath(Graph graph) throws IOException;
+
 }
diff --git a/src/main/org/insa/graph/io/AbstractPathWriter.java b/src/main/org/insa/graph/io/AbstractPathWriter.java
new file mode 100644
index 0000000..0e27037
--- /dev/null
+++ b/src/main/org/insa/graph/io/AbstractPathWriter.java
@@ -0,0 +1,18 @@
+package org.insa.graph.io;
+
+import java.io.IOException;
+
+import org.insa.graph.Path;
+
+public interface AbstractPathWriter {
+
+    /**
+     * Write a path.
+     * 
+     * @param path Path to write.
+     * 
+     * @throws Exception
+     */
+    public void writePath(Path path) throws IOException;
+
+}
diff --git a/src/main/org/insa/graph/io/BinaryPathReader.java b/src/main/org/insa/graph/io/BinaryPathReader.java
index 6f2eeeb..53ae922 100644
--- a/src/main/org/insa/graph/io/BinaryPathReader.java
+++ b/src/main/org/insa/graph/io/BinaryPathReader.java
@@ -11,55 +11,55 @@ import org.insa.graph.Path.CreationMode;
 
 public class BinaryPathReader extends BinaryReader implements AbstractPathReader {
 
-	// Map version and magic number targeted for this reader.
-	private static final int VERSION = 1;
-	private static final int MAGIC_NUMBER = 0xdecafe;
+    // Map version and magic number targeted for this reader.
+    protected static final int VERSION = 1;
+    protected static final int MAGIC_NUMBER = 0xdecafe;
 
-	public BinaryPathReader(DataInputStream dis) {
-		super(MAGIC_NUMBER, VERSION, dis);
-	}
+    public BinaryPathReader(DataInputStream dis) {
+        super(MAGIC_NUMBER, VERSION, dis);
+    }
 
-	@Override
-	public Path readPath(Graph graph) throws Exception {
-		
-		// Read and check magic number and version.
-		checkMagicNumberOrThrow(dis.readInt());
-		checkVersionOrThrow(dis.readInt());
-		
-		// Read map ID and check against graph.
-		int mapId = dis.readInt();
-		
-		if (mapId != graph.getMapId()) {
-			throw new MapMismatchException(mapId, graph.getMapId());
-		}
-		
-		// Number of nodes in the path (without first and last).
-		int nbNodes = dis.readInt();
-				
-		// Skip (duplicate) first and last node
-		readNode(graph);
-		readNode(graph);
-		
-		// Read intermediate nodes:
-		ArrayList<Node> nodes = new ArrayList<Node>();
-		for (int i = 0; i < nbNodes; ++i) {
-			nodes.add(readNode(graph));
-		}
-		
-		return new Path(graph, nodes, CreationMode.SHORTEST_TIME);
-	}
+    @Override
+    public Path readPath(Graph graph) throws IOException {
 
-	/**
-	 * Read a node from the stream and returns id.
-	 * 
-	 * @return
-	 * @throws IOException 
-	 */
-	protected Node readNode(Graph graph) throws IOException {
-		// Discard zone.
-		dis.readUnsignedByte();
-		
-		return graph.getNodes().get(read24bits());
-	}
+        // Read and check magic number and version.
+        checkMagicNumberOrThrow(dis.readInt());
+        checkVersionOrThrow(dis.readInt());
+
+        // Read map ID and check against graph.
+        int mapId = dis.readInt();
+
+        if (mapId != graph.getMapId()) {
+            throw new MapMismatchException(mapId, graph.getMapId());
+        }
+
+        // Number of nodes in the path (without first and last).
+        int nbNodes = dis.readInt();
+
+        // Skip (duplicate) first and last node
+        readNode(graph);
+        readNode(graph);
+
+        // Read intermediate nodes:
+        ArrayList<Node> nodes = new ArrayList<Node>();
+        for (int i = 0; i < nbNodes; ++i) {
+            nodes.add(readNode(graph));
+        }
+
+        return new Path(graph, nodes, CreationMode.SHORTEST_TIME);
+    }
+
+    /**
+     * Read a node from the stream and returns id.
+     * 
+     * @return
+     * @throws IOException
+     */
+    protected Node readNode(Graph graph) throws IOException {
+        // Discard zone.
+        dis.readUnsignedByte();
+
+        return graph.getNodes().get(read24bits());
+    }
 
 }
diff --git a/src/main/org/insa/graph/io/BinaryPathWriter.java b/src/main/org/insa/graph/io/BinaryPathWriter.java
new file mode 100644
index 0000000..b8cce09
--- /dev/null
+++ b/src/main/org/insa/graph/io/BinaryPathWriter.java
@@ -0,0 +1,44 @@
+package org.insa.graph.io;
+
+import java.io.DataOutputStream;
+import java.io.IOException;
+
+import org.insa.graph.Arc;
+import org.insa.graph.Path;
+
+public class BinaryPathWriter extends BinaryWriter implements AbstractPathWriter {
+
+    /**
+     * @param dos
+     */
+    protected BinaryPathWriter(DataOutputStream dos) {
+        super(dos);
+    }
+
+    @Override
+    public void writePath(Path path) throws IOException {
+
+        // Write magic number and version.
+        dos.writeInt(BinaryPathReader.MAGIC_NUMBER);
+        dos.writeInt(BinaryPathReader.VERSION);
+
+        // Write map id.
+        dos.writeInt(path.getGraph().getMapId());
+
+        // Write number of racs
+        dos.writeInt(path.getArcs().size() + 1);
+
+        // Write origin / destination.
+        dos.writeInt(path.getOrigin().getId());
+        dos.writeInt(path.getDestination().getId());
+
+        // Write nodes.
+        dos.writeInt(path.getOrigin().getId());
+        for (Arc arc: path.getArcs()) {
+            dos.writeInt(arc.getDestination().getId());
+        }
+
+        dos.flush();
+    }
+
+}
diff --git a/src/main/org/insa/graph/io/BinaryWriter.java b/src/main/org/insa/graph/io/BinaryWriter.java
new file mode 100644
index 0000000..43e5cf7
--- /dev/null
+++ b/src/main/org/insa/graph/io/BinaryWriter.java
@@ -0,0 +1,30 @@
+package org.insa.graph.io;
+
+import java.io.DataOutputStream;
+import java.io.IOException;
+
+public abstract class BinaryWriter {
+
+    // Output stream.
+    protected DataOutputStream dos;
+
+    /**
+     * @param dos
+     */
+    protected BinaryWriter(DataOutputStream dos) {
+        this.dos = dos;
+    }
+
+    /**
+     * Write a 24-bits integer in BigEndian to the output stream.
+     * 
+     * @param value
+     * 
+     * @throws IOException
+     */
+    protected void write24bits(int value) throws IOException {
+        dos.writeShort(value >> 8);
+        dos.writeByte(value & 0xff);
+    }
+
+}
diff --git a/src/main/org/insa/graph/io/MapMismatchException.java b/src/main/org/insa/graph/io/MapMismatchException.java
index 10b0fd2..79be472 100644
--- a/src/main/org/insa/graph/io/MapMismatchException.java
+++ b/src/main/org/insa/graph/io/MapMismatchException.java
@@ -1,36 +1,38 @@
 package org.insa.graph.io;
 
-public class MapMismatchException extends Exception {
+import java.io.IOException;
 
-	/**
-	 * 
-	 */
-	private static final long serialVersionUID = 3076730078387819138L;
-	// Actual and expected magic numbers.
-	private int actualMapId, expectedMapId;
-	
-	/**
-	 * 
-	 * @param actualVersion
-	 * @param expectedVersion
-	 */
-	public MapMismatchException(int actualMapId, int expectedMapId) {
-		super();
-		this.actualMapId = actualMapId;
-		this.expectedMapId = expectedMapId;
-	}
+public class MapMismatchException extends IOException {
 
-	/**
-	 * @return
-	 */
-	public int getActualMapId() {
-		return actualMapId;
-	}
+    /**
+     * 
+     */
+    private static final long serialVersionUID = 3076730078387819138L;
+    // Actual and expected magic numbers.
+    private int actualMapId, expectedMapId;
 
-	/**
-	 * @return
-	 */
-	public int getExpectedMapId() {
-		return expectedMapId;
-	}
+    /**
+     * 
+     * @param actualVersion
+     * @param expectedVersion
+     */
+    public MapMismatchException(int actualMapId, int expectedMapId) {
+        super();
+        this.actualMapId = actualMapId;
+        this.expectedMapId = expectedMapId;
+    }
+
+    /**
+     * @return
+     */
+    public int getActualMapId() {
+        return actualMapId;
+    }
+
+    /**
+     * @return
+     */
+    public int getExpectedMapId() {
+        return expectedMapId;
+    }
 }