A bus

The omnibus, the first organized public transport system, may have originated in Nantes, France in 1826, when Stanislas Baudry, a retired army officer who had built public baths (run from the surplus heat from his flour mill) on the city's edge, set up a short stage line between the center of town and his baths. The service started on the Place du Commerce, outside the hat shop of M. Omnès, who displayed the motto Omnès Omnibus ("Omnès for all") on his shopfront. When Baudry discovered that passengers were just as interested in getting off at intermediate points as in patronizing his baths, he shifted the stage line's focus. His new voiture omnibus ("carriage for all") combined the functions of the hired hackney carriage with the stagecoach that travelled a predetermined route from inn to inn, carrying passengers and mail. His omnibus featured wooden benches that ran down the sides of the vehicle; entry was from the rear.
A bus in Cúcuta, Colombia in 1920
A bus in Cúcuta, Colombia in 1920

There is also a claim from the UK where in 1824 John Greenwood operated the first "bus route" from Market Street in Manchester to Pendleton in Salford.[1]

Whether by direct emulation, or because the idea was in the air, by 1832 the idea had been copied in Paris, Bordeaux and Lyons. A London newspaper reported in July 4, 1829 that "the new vehicle, called the omnibus, commenced running this morning from Paddington to the City". This bus service was operated by George Shillibeer.