Container flows are strongly linked to economic development. The more money people have, the more goods they are able to buy. Trade is at the core of the modern global economy and the is the fuel for globalisation.
Donald Trump thinks NAFTA is the worst trade deal ever made. So what is the impact of a trade deal? Are they worth signing in the first place? A lot of factors influence volumes of trade before and after trade deals are signed, but all signs point toward NAFTA stimulating rather than damaging the US.