no, i think that no matter what the identity of the USA is going to stay the same for a long time. I think that not matter what we are going to stay seen as the strongest and wealthiest country in the world, and that no one is going to rise higher.
Even if we were to live in a country with no roads or bridges, we would still be Americans. Most Americans derive approximately 0% of their identities from the interstate highway system. Things would certainly be more difficult and the population would become much less mobile, but people wouldn't start calling themselves Mexicans or Canadians just because a bridge falls down.
I do not think that the deterioration of America's infrastructure is become too rapid to stop. And I think that stopping it doesn't mean that the identity of the nation at large needs to be sacrificed. All it is going to take is the American people working together to work towards a goal.
America's infrastructure might get worse before it gets better, but anytime we lose something, we tend to come back stronger. There was definitely an identity shift and sacrifice when the infrastructure was changed from railroads to cars and later freeways, but there is not likely going to be another identity loss or change with upcoming infrastructure improvements.
In fact, I saw vast improvements done very quickly where I live in New York State. It is in Dutchess country. There was an infrastructure upgrade done extremely quickly over the course of a couple of months, and it was impressive. This could be done country wide within a year's time.