As seen on the Prisoner of Azkaban.
The Knight Bus is a vehicle from the Harry Potter Universe. Witches and Wizards can summon it to their location by holding their wand hand out into the road. The vehicle is enchanted, and can magically fit through small gaps, brake in an instant and travel at near impossible speeds. Aboard the bus, there are two settings for different times. During the day, the bus is set out with chairs, but at night, it is set out with beds across all three floors, and for a small fee added onto the price of the journey, access to certain amenities, such as a hot water bottle or hot chocolate is offered.