I read I think it was in the book Never Stand Still which was the corporate story of Consolidated Freightways,that Pennsylvania and Iowa hate doubles and never liked them. They were like the 2 last states to allow doubles on their roads and what happened was the trucking industry lobbied the federal government to basically withhold tax dollars for roads and stuff to all states that didn't allow doubles. Pennsylvania and Iowa then relinquished and allowed doubles after that, because they wanted federal dollars for roads.
I think there was a time when CF had shuttle drivers who would shuttle trailers from Erie, PA to the New York State boarder. The doubles would stop in like will just say Ashtabula, Ohio they would break them into singles and shuttle the trailers one at a time across the top of Pennsylvania to New York State and then they would re hook and go on their way.