diff --git a/README.md b/README.md
index fd81c2eb7d7957ed75299a996c501cd788cd3351..3429d11a6e703b8a87b745cf8ef114bc3571872b 100644
--- a/README.md
+++ b/README.md
@@ -57,7 +57,7 @@ This package file includes a launch file named spawn_road.launch which is intend
 
 * **road_name**: (default=road) name of the road image to be used (without the .png extension). This name will also be used to name the nodes and topics associated with the road description.
 * **road_size**: (default=15.0) size of the road in meters. At the moment only square road images are supported.
-* **road_path**: (default=$(env HOME)/Downloads) path where the road image is located.
+* **road_path**: (default=$(env HOME)/Downloads) path where the road image is located. It must be and absolute path.
 * **x** (default=0.0) x position where the road will placed in the simulated environment with respect to the parent frame.
 * **y** (default=0.0) y position where the road will placed in the simulated environment with respect to the parent frame.
 * **yaw** (default=0.0) orientation of the road with respect to the parent frame.