Hansom cab
From Tardis Wiki, the free Doctor Who reference
A Hansom cab is a type of carriage with two wheels. The passengers sit below the driver in a space which can be enclosed, and the driver sits above and behind the passengers.
Li H'sen Chang and Mr Sin rode in a hansom cab while searching London. (TV: The Talons of Weng-Chiang)
A hansom cab passes between the Eleventh Doctor and Strax, Jenny and Vastra as he walks away from them. After the cab passes, the Doctor has disappeared. (TV: The Great Detective)