Secondly these are bridges and roads that are going to to be fixed anyways, so as far as economic growth is concerned, it's a wash. The Federal Government has to take money out of the private economy on top of that to pay for it, so there is no net gain of wealth to the Economy. It's a shifting of resources. Nothing more. You are falling for an economic fallacy.
That Which is Seen, and That Which is Not Seen; by Frederic Bastiat