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. They discovered that bus fares had gone up during their time away. (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)