Hansom cab so named in mid 19th century: named after Joseph A. Hansom (1803–82), English architect, patentee of such a cab in 1834.

The Hansom Cab rapidly gained popularity and began to replace the Hackney Carriage, offering more stability and speed than its predecessor. They could be drawn by one horse alone, improving cost-effectiveness. 

The Mystery of a Hansom Cab depicts a dramatic murder taking place in Colonial Melbourne, detailing the efforts that a detective of the police force must go through in order to solve this crime, serving to inspire thought into the cultural and political context of the mid-1800s.

Hanson is a patronymic name that means "son of Hans".  The name Hanson has multiple origins, including Scandinavian, German, English, Irish, and Jewish.  Hanson is also an Americanized form of the Norwegian, Danish, Dutch, or North German name Hansen and Hanssen.  Hanson is also an Americanized form of the Swedish name Hansson. 

Just now, drpaladin said:

Look Ma, no hans.

And cabs and cabbies are no longer hansom.