Many people are inconsistent in their pronunciation of "route." On YouTube videos about pronunciation, they say that a highway is called a "root", but that in the stock phrase "If you want to go that route..." they make it rhyme with "out".

Such people are from both sides of the pond. I do it too.

Long ago there was a TV show called "Root 66." I bet its theme song had a lot to do with the preference for the oo sound today.