Is it illegal to park on the side of the road for a few minutes?

No, just a temporary parking. Parking is divided into temporary parking and vehicle parking: temporary parking refers to people and vehicles leaving the car. Parking means the separation of vehicles after parking. Therefore, the distinction between motor vehicle parking and temporary parking mainly depends on whether the driver leaves the vehicle: if the driver stops at the roadside for a short time and leaves immediately after getting on or off the bus or loading and unloading goods, it is temporary parking.