(25 Apr 2022, 4:23 pm)Unber43 wrote This is just a general thing - but are drivers allowed to wear one airpod in the right side?

The fact that they're only using one, in the side that's facing away from most people's line of sight, probably answers that. 

Ultimately it's probably for similar reasons to why passengers are advised not to distract the driver (i.e try and have conversation) without due cause - if a driver is listening to their playlist on full blast they're likely to be distracted/not as responsive to other sounds on the vehicle that may need their attention (bells, passengers informing driver of actual vehicle issues, warning buzzers, passenger falls etc).