diff --git a/brouter-server/src/main/java/btools/server/RouteServer.java b/brouter-server/src/main/java/btools/server/RouteServer.java
index c3953e1..57689a4 100644
--- a/brouter-server/src/main/java/btools/server/RouteServer.java
+++ b/brouter-server/src/main/java/btools/server/RouteServer.java
@@ -36,6 +36,11 @@ import btools.util.StackSampler;
 public class RouteServer extends Thread
 {
   public static final String PROFILE_UPLOAD_URL = "/brouter/profile";
+  static final String HTTP_STATUS_OK = "200 OK";
+  static final String HTTP_STATUS_BAD_REQUEST = "400 Bad Request";
+  static final String HTTP_STATUS_FORBIDDEN = "403 Forbidden";
+  static final String HTTP_STATUS_NOT_FOUND = "404 Not Found";
+  static final String HTTP_STATUS_INTERNAL_SERVER_ERROR = "500 Internal Server Error";
 
 	public ServiceContext serviceContext;
 
@@ -80,6 +85,8 @@ public class RouteServer extends Thread
               String line = br.readLine();
               if ( line == null )
               {
+                writeHttpHeader(bw, HTTP_STATUS_BAD_REQUEST);
+                bw.flush();
                 return;
               }
               if ( line.length() == 0 )
@@ -108,7 +115,7 @@ public class RouteServer extends Thread
               {
                 if ( agent.indexOf( tk.nextToken() ) >= 0 )
                 {
-                  writeHttpHeader( bw );
+                  writeHttpHeader( bw, HTTP_STATUS_FORBIDDEN );
                   bw.write( "Bad agent: " + agent );
                   bw.flush();
                   return;
@@ -118,11 +125,13 @@ public class RouteServer extends Thread
 
             if ( getline.startsWith("GET /favicon.ico") )
             {
-            	return;
+              writeHttpHeader( bw, HTTP_STATUS_NOT_FOUND );
+              bw.flush();
+              return;
             }
             if ( getline.startsWith("GET /robots.txt") )
             {
-              writeHttpHeader( bw );
+              writeHttpHeader( bw, HTTP_STATUS_OK );
               bw.write( "User-agent: *\n" );
               bw.write( "Disallow: /\n" );
               bw.flush();
@@ -149,13 +158,13 @@ public class RouteServer extends Thread
                 // handle CORS preflight request (Safari)
                 String corsHeaders = "Access-Control-Allow-Methods: GET, POST\n"
                                    + "Access-Control-Allow-Headers: Content-Type\n";
-                writeHttpHeader( bw, "text/plain", null, corsHeaders );
+                writeHttpHeader( bw, "text/plain", null, corsHeaders, HTTP_STATUS_OK );
                 bw.flush();
                 return;
               }
               else
               {
-                writeHttpHeader(bw, "application/json");
+                writeHttpHeader(bw, "application/json", HTTP_STATUS_OK);
 
                 String profileId = null;
                 if ( url.length() > PROFILE_UPLOAD_URL.length() + 1 )
@@ -173,13 +182,15 @@ public class RouteServer extends Thread
             }
             else if ( url.startsWith( "/brouter/suspects" ) )
             {
-              writeHttpHeader(bw, url.endsWith( ".json" ) ? "application/json" : "text/html");
+              writeHttpHeader(bw, url.endsWith( ".json" ) ? "application/json" : "text/html", HTTP_STATUS_OK);
               SuspectManager.process( url, bw );
               return;
             }
             else
             {
-            	throw new IllegalArgumentException( "unknown request syntax: " + getline );
+              writeHttpHeader( bw, HTTP_STATUS_NOT_FOUND );
+              bw.flush();
+              return;
             }
             RoutingContext rc = handler.readRoutingContext();
             List<OsmNodeNamed> wplist = handler.readWayPointList();
@@ -214,7 +225,7 @@ public class RouteServer extends Thread
 
             if ( cr.getErrorMessage() != null )
             {
-              writeHttpHeader(bw);
+              writeHttpHeader(bw, HTTP_STATUS_INTERNAL_SERVER_ERROR);
               bw.write( cr.getErrorMessage() );
               bw.write( "\n" );
             }
@@ -223,7 +234,7 @@ public class RouteServer extends Thread
               OsmTrack track = cr.getFoundTrack();
               
               String headers = encodings == null || encodings.indexOf( "gzip" ) < 0 ? null : "Content-Encoding: gzip\n";
-              writeHttpHeader(bw, handler.getMimeType(), handler.getFileName(), headers );
+              writeHttpHeader(bw, handler.getMimeType(), handler.getFileName(), headers, HTTP_STATUS_OK );
               if ( track != null )
               {
                 if ( headers != null ) // compressed
@@ -245,6 +256,11 @@ public class RouteServer extends Thread
           }
           catch (Throwable e)
           {
+             try {
+               writeHttpHeader(bw, HTTP_STATUS_INTERNAL_SERVER_ERROR);
+               bw.flush();
+             }
+             catch (IOException _ignore){}
              System.out.println("RouteServer got exception (will continue): "+e);
              e.printStackTrace();
           }
@@ -369,25 +385,25 @@ public class RouteServer extends Thread
     return maxRunningTime;
   }
 
-  private static void writeHttpHeader( BufferedWriter bw ) throws IOException
+  private static void writeHttpHeader( BufferedWriter bw, String status ) throws IOException
   {
-    writeHttpHeader( bw, "text/plain" );
+    writeHttpHeader( bw, "text/plain", status );
   }
 
-  private static void writeHttpHeader( BufferedWriter bw, String mimeType ) throws IOException
+  private static void writeHttpHeader( BufferedWriter bw, String mimeType, String status ) throws IOException
   {
-    writeHttpHeader( bw, mimeType, null );
+    writeHttpHeader( bw, mimeType, null, status );
   }
 
-  private static void writeHttpHeader( BufferedWriter bw, String mimeType, String fileName ) throws IOException
+  private static void writeHttpHeader( BufferedWriter bw, String mimeType, String fileName, String status ) throws IOException
   {
-    writeHttpHeader( bw, mimeType, fileName, null);
+    writeHttpHeader( bw, mimeType, fileName, null, status);
   }
 
-  private static void writeHttpHeader( BufferedWriter bw, String mimeType, String fileName, String headers ) throws IOException
+  private static void writeHttpHeader( BufferedWriter bw, String mimeType, String fileName, String headers, String status ) throws IOException
   {
     // http-header
-    bw.write( "HTTP/1.1 200 OK\n" );
+    bw.write( String.format("HTTP/1.1 %s\n", status) );
     bw.write( "Connection: close\n" );
     bw.write( "Content-Type: " + mimeType + "; charset=utf-8\n" );
     if ( fileName != null )