diff --git a/modules/planning/traffic_rules/util.h.old b/modules/planning/traffic_rules/util.h.old
deleted file mode 100644
index 6b6fc4890041f2f480f756f13e054f7fc7fce056..0000000000000000000000000000000000000000
--- a/modules/planning/traffic_rules/util.h.old
+++ /dev/null
@@ -1,35 +0,0 @@
-/******************************************************************************
- * Copyright 2018 The Apollo Authors. All Rights Reserved.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *****************************************************************************/
-
-/**
- * @file util.h
- **/
-
-#pragma once
-
-#include "modules/planning/common/reference_line_info.h"
-
-namespace apollo {
-namespace planning {
-namespace util {
-
-double GetADCStopDeceleration(ReferenceLineInfo* const reference_line_info,
-                              const double stop_line_s,
-                              const double min_pass_s_distance);
-
-}  // namespace util
-}  // namespace planning
-}  // namespace apollo