Because Britain.
I've been in Italy when a road needed repair, and they just closed the road and got the f'ck on with it. 3 mile section done in 1 week - as in, completely dug up and relaid.
In this country they would take 10 years to plan it, and then do it at a rate of 1 mile a month. And it would be a patchwork special covered with chippings. And they would pay a number of incompetent, over priced contractors to repeat their sh*tty work many times over.