diff --git a/osi_trafficlight.proto b/osi_trafficlight.proto
index 4ecead3b2..0aef80e7c 100644
--- a/osi_trafficlight.proto
+++ b/osi_trafficlight.proto
@@ -35,6 +35,13 @@ message TrafficLight
     //
     optional Classification classification = 3;
 
+    // Opaque reference of an associated 3D model of the traffic light.
+    //
+    // \note It is implementation-specific how model_references are resolved to
+    // 3d models.
+    //
+    optional string model_reference = 4;
+
     //
     // \brief \c Classification data for a traffic light.
     //
diff --git a/osi_trafficsign.proto b/osi_trafficsign.proto
index 77a69b823..3c9ac589b 100644
--- a/osi_trafficsign.proto
+++ b/osi_trafficsign.proto
@@ -181,6 +181,13 @@ message TrafficSign
         //
         optional Classification classification = 2;
 
+        // Opaque reference of an associated 3D model of the traffic sign.
+        //
+        // \note It is implementation-specific how model_references are resolved to
+        // 3d models.
+        //
+        optional string model_reference = 3;
+
         //
         // \brief \c Classification data for a traffic sign.
         //
@@ -5459,6 +5466,13 @@ message TrafficSign
         //
         optional Classification classification = 2;
 
+        // Opaque reference of an associated 3D model of the supplementary traffic sign.
+        //
+        // \note It is implementation-specific how model_references are resolved to
+        // 3d models.
+        //
+        optional string model_reference = 3;
+
         //
         // \brief \c Classification data for a supplementary traffic sign.
         //