Thank you very much, sdgraham.You are correct, " fastest speed" is redundant
Thank you very much, lingo.
Thank you very much, Egmont.Speed is a number, and numbers don't move - so "fastest speed" is not just redundant, it is logically incorrect. It should be either "fastest," without "speed," or "highest speed."
Thank you very much, pops.fast, faster, fastest imply speed: "moving, operating, or acting quickly
a fast train
a fast thinker
: the act or state of moving swiftly
b: rate of motion: such as
(1): VELOCITY sense 1
(2): the magnitude of a velocity irrespective of direction
In some respects I disagree with Egmont. Though he may be technically correct, you will often see the term fastest speed used in English.
To wit: What’s the Fastest Speed Ever Achieved By a Human Being?
and Fastest speed recorded for a battleship