diff -u -r1.11 -r1.12
--- HelixUtils.java	14 Nov 2010 00:33:25 -0000	1.11
+++ HelixUtils.java	1 Feb 2011 22:45:05 -0000	1.12
@@ -77,8 +77,34 @@

      * @return path length from the DCA to the hit
      */
     public static double PathLength(HelicalTrackFit helix, HelicalTrackHit hit) {

-        //  Return the path length from the DCA
-        return PathCalc(helix.xc(), helix.yc(), helix.R(), helix.x0(), helix.y0(), hit.x(), hit.y());

+
+        //  Calculate the shortest path length from the DCA to the hit x-y coordinates
+        double path0 = PathCalc(helix.xc(), helix.yc(), helix.R(), helix.x0(), helix.y0(), hit.x(), hit.y());
+        if (hit instanceof HelicalTrack2DHit) return path0;
+
+        //  Find the closest 3D hit in the z coordinate (if there is one)
+        HelicalTrackHit close = null;
+        double zhit = hit.z();
+        for (HelicalTrackHit fithit : helix.PathMap().keySet()) {
+            if (!(fithit instanceof HelicalTrack2DHit)) {
+
+                 if (close == null) {
+                    //  If this is the first 3D hit, mark it as being closest
+                    close = fithit;
+                } else {
+                    //  Check if the fithit is closer in z
+                    if (Math.abs(zhit - fithit.z()) < Math.abs(zhit - close.z())) close = fithit;
+                }
+            }
+        }
+
+        //  If we didn't find another 3D hit, return the path from the DCA
+        if (close == null) return path0;
+
+        //  Find the path length for the closest hit assuming it hasn't looped
+        double path = helix.PathMap().get(close) +
+                PathCalc(helix.xc(), helix.yc(), helix.R(), close.x(), close.y(), hit.x(), hit.y());
+        return path;

     }
     
     /**