Is it permitted to remove one of the hands from the steering wheel or the handlebars while driving?

The correct answer: Forbidden, except to change gear or to signal with the direction indicator (winker) or to ensure the proper functioning of the vehicle.

You should keep both hands on the steering wheel or handlebars for full control. Removing a hand is forbidden, except to change gear, to signal with the direction indicator, or to ensure the proper functioning of the vehicle. Tuning the radio or using a phone are not exceptions.