Updated the documentation.

README.md

@@ -47,11 +47,13 @@ To generate new road images, follow the next steps:
 convert <original_image> -density <new_ppi_value> -units PixelsPerInch <modified_image>
 ```
 
+* The actual ppi of the new image may be not exactly the same as the desired one. To take this into account, the launch files accept a *road_size* parameter to set the actual size of the road. See the [launch](#launch) section.
+
 * This packages includes a script to create a link to the actual road image, so it is not necessary to copy it anywhere. See the [launch](#launch) section.
 
 ## Launch
 
-This package file includes a launch file named spawn_road.launch which is intended to be included from other launch file that requires to spawn a road in a simulated Gazebo world. This launch file has two parameters:
+This package file includes a launch file named spawn_road.launch which is intended to be included from other launch file that requires to spawn a road in a simulated Gazebo world. This launch file has the following parameters:
 
 * **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.

urdf/roads/dae/png/README.md

-Download images from shared drive space LaboratoriIRI/Projects/ADC/simulator/roads/*.png