Why are we afraid of a highway across North America?

Maybe I am just not enough of a conspiracy theorist lately. As one who likes to occasionally vacation in Mexico, one foreign country where my American dollar is still worth something, I really do not understand how building a superhighway linking Canada, the United States, and Mexico means that we are necessarily moving toward world government and a loss of sovereignty. Apparently it is a major concern of a majority of Arizona's state Senators. Now if only these people could do something important, like pass a budget so our entire state doesn't close down on July 1.