diff --git a/include/opendrive_lane.h b/include/opendrive_lane.h
index 10b99775e8ee286316c2972ffe540978278d7b73..e03e4908a66c8979e5477f608e97591e2aefe1ef 100644
--- a/include/opendrive_lane.h
+++ b/include/opendrive_lane.h
@@ -77,8 +77,8 @@ class COpendriveLane
     TOpendriveWorldPose get_start_pose(void) const;
     TOpendriveWorldPose get_end_pose(void) const;
     double get_length(void) const;
-    TOpendriveWorldPose get_pose_at(double length);
-    double get_curvature_at(double length);    
+    TOpendriveWorldPose get_pose_at(double length) const;
+    double get_curvature_at(double length) const;    
     TOpendriveLocalPose transform_to_local_pose(TOpendriveTrackPose &track) const;
     TOpendriveWorldPose transform_to_world_pose(TOpendriveTrackPose &track) const;
     const COpendriveRoadNode &get_closest_node(TOpendriveWorldPose &pose,double &distance,double angle_tol=0.1) const;
diff --git a/src/opendrive_lane.cpp b/src/opendrive_lane.cpp
index 035100b03ed1c619ff82b26e11fc75173a9a1255..65cc184389c03bed82496103af77e1f2c4d0baf5 100644
--- a/src/opendrive_lane.cpp
+++ b/src/opendrive_lane.cpp
@@ -711,7 +711,7 @@ double COpendriveLane::get_length(void) const
   return length;
 }
 
-TOpendriveWorldPose COpendriveLane::get_pose_at(double length)
+TOpendriveWorldPose COpendriveLane::get_pose_at(double length) const
 {
   TOpendriveWorldPose world_pose={0};
 
@@ -735,7 +735,7 @@ TOpendriveWorldPose COpendriveLane::get_pose_at(double length)
   return world_pose;
 }
 
-double COpendriveLane::get_curvature_at(double length)
+double COpendriveLane::get_curvature_at(double length) const
 {
   double curvature;