Grunden er, at busserne, såvel bybusserne som turistbusserne, ofte kører i de smalle gader i bymidterne i myldretiden, når der også færdes mange biler, motorcykler, cykler og fodgængere på gaden.
The reason is that buses - both inner-city buses and coaches - often have to operate in narrow streets in city centres during the rush hours, when many other vehicles, motorbikes, bikes, and pedestrians are on the road.