Personal mobility vehicles, such as electric scooters and electric unicycles, have certain restrictions regarding where they can circulate. According to the regulations, **they cannot circulate on highways and expressways**. This is because these roads are designed for vehicles that can maintain higher speeds and have specific safety features that are not suitable for personal mobility vehicles.

Furthermore, highways and expressways are fast roads where pedestrians, animals, bicycles, mopeds, and vehicles for people with reduced mobility are also not allowed to circulate. This reinforces the idea that these roads are neither safe nor suitable for personal mobility vehicles, regardless of the driver's age or whether the road is within a town. Therefore, the correct answer is that **it is not permitted for a personal mobility vehicle to circulate on an expressway**.