Is it okay to use a windscreen wiper when driving on a highway?

I asked my friend to lend me his car and he agreed. However, there’s one condition: I don’t touch his car’s windshield wipers.<br><br>I only asked him because I recently noticed that the windshield wipers of his car were exceptionally sturdy and strong, and I assumed they would be useful for a long highway drive. Nevertheless, I accepted his terms and conditions.<br><br>He also asked me not to smoke inside the car or to bring smelly foods inside. All of which I agreed to.<br><br>Is there anything wrong with using windshield wipers on a highway?