“potentially obscuring vision”
Saw a bus driver almost hit a woman crossing the highway. I was close enough I would have had blood splatter and body parts on my windshield. Driver was looking through 3 layers of shield, a windshield, face shield and glasses. I don’t think he saw her.
Another case I hadnt thought of, but yes, makes no sense whatsoever to encumber a driver of ANY vehicle with a mask. I still fly passenger aircraft two weekends a month. I would never fly with a mask. How is driving a bus any different.