Following the end of the empire and the dissolution of the estate, if you will, a select number of Imperial carriages were kept as mementos, and in 1922 were moved to the old winter riding school on the grounds of Schloss Schönbrunn and installed as one of its museums.
The most impressive carriage for living royalty is without doubt the Coronation Carriage, built in the late 1700’s and used for Habsburg coronations. This carriage weighs 4.000kg and even being drawn by eight horses, could not proceed at more than a walking pace. 
Emperors and Empresses each needed more than one style of carriage, naturally, and below are a couple of “knocking about town” buggies.

Come warm weather, when the family spent their days at their summer palace, Schloss Schönbrunn, this was their everyday ride, pulled by six white stallions. Where they would go, I do not know.

No ordinary tack for the Imperial horses, either.
Even little royalty had carriages. This was designed for the son of Napoleon and his second wife, Maria Louisa (a Habsburg princess). But little royalty did not require stallions for power; this carriage was pulled by sheep.

And even in death, appearances must be maintained.  The Black Hearse of the Royal Court was pulled by eight black horses, and was last used in 1989 for the funeral of Empress Zita, who died in exile in Switzerland at the age of 96.