Bus

Buses were large, four-wheeled vehicles, sometimes with two floors, used on Earth, capable of transporting many more passengers than a standard automobile. They often bore numbers associated with routes so that passengers could know which specific bus to ride in order to get to a particular place.

History
Upon returning to London, one of Ian and Barbara's first acts was to use the bus system to sightsee around central London. (DW: "The Planet of Decision") Nostalgia Tours converted a space cruiser to have the chassis of a bus when it was due to travel to Earth, 1959. It was capable of flight, and was powered by a Hellstorm Fireball engine. It was destroyed by the Bannermen. (DW: Delta and the Bannermen)

The Eighth Doctor commandeered a double-decker bus after its driver was killed. (DWM: Doctor Who and the Nightmare Games)

Iris Wildthyme's TARDIS assumed the shape of the number 22 bus that often circled Putney Common. (ST: Old Flames)

In 1843, the Metropolitan Police Service wrote off the deaths of seven civilians and a policeman as the result of a bus crushing them. They had in fact been killed by stone lions. (ST: The Lions of Trafalgar)

Dodo Chaplet told Steven Taylor that, if she got lost, she would catch a bus to return to the TARDIS. (DW: The Ark)

A tour bus took Maria Jackson and Kelsey Hooper to the Bubble Shock! factory. Later, Sarah Jane Smith broke into the factory with one of these buses, crashing the door. (SJA: Invasion of the Bane)

The 200 was another London double-decker bus. It fell through a wormhole to the planet San Helios. Its sturdy construction and metallic frame protected the occupants. The Tenth Doctor fitted it with anti-gravity clamps, making it capable of flight; it was then flown through the wormhole to Earth. Lady Christina de Souza then flew off in it. (DW: Planet of the Dead)

Amy Pond and Rory Williams once had to catch a ride in a school bus in Utah in order to recommence their travels with the Eleventh Doctor. (DW: The Impossible Astronaut)