diff --git a/katana/src/NegociateWindow.cpp b/katana/src/NegociateWindow.cpp
index 63de0af2..43c894a6 100644
--- a/katana/src/NegociateWindow.cpp
+++ b/katana/src/NegociateWindow.cpp
@@ -327,11 +327,15 @@ namespace Katana {
 
       cdebug_log(159,0) << "* Nearest " << track << endl;
 
+      if (not track)
+        throw Error( "NegociateWindow::createTracksegment(): No track near axis of %s."
+                   , getString(autoSegment).c_str() );
+
       if (track->getAxis() > uside.getVMax()) track = track->getPreviousTrack();
       if (track->getAxis() < uside.getVMin()) track = track->getNextTrack();
 
       if (not track)
-        throw Error( "NegociateWindow::createTracksegment(): No track near axis of %s."
+        throw Error( "NegociateWindow::createTracksegment(): No track near axis of %s (after adjust)." 
                    , getString(autoSegment).c_str() );
 
       cdebug_log(159,0) << "* GCell U-side " << uside << endl;
diff --git a/katana/src/RoutingPlane.cpp b/katana/src/RoutingPlane.cpp
index 92f8bd32..ef6d702a 100644
--- a/katana/src/RoutingPlane.cpp
+++ b/katana/src/RoutingPlane.cpp
@@ -162,11 +162,14 @@ namespace Katana {
 
   Track* RoutingPlane::getTrackByPosition ( DbU::Unit axis, uint32_t mode ) const
   {
-    return getTrackByIndex( getLayerGauge()->getTrackIndex( getAxisMin()
-                                                          , getAxisMax()
-                                                          , axis
-                                                          , mode
-                                                          ) );
+    size_t index = getLayerGauge()->getTrackIndex( getAxisMin(), getAxisMax(), axis, mode );
+    if (index == getTracksSize()) {
+      if (not index) return NULL;
+      if ((mode == Constant::Superior) or (mode == Constant::Exact)) return NULL;
+      --index;
+    }
+
+    return getTrackByIndex( index );
   }