Your point is.
Do the tool roads in Mexico make money when there are no customers that pay?
Well most turistas will not have the answer and trying to get any info from the Mexican government will be like pulling teeth from a hungry lion, as in not possible for foreigners to obtain.
They must be doing some thing right since some of those toll roads have been in operation for a very long time as in maybe 50 yeras or more,I know that the toll road from Mexico City to puebla was built in the earlly sixties and the one to Cuernavaca in the late fifties, did they go bankrupt? we will probablly never know, do they make money? who knows.
You can not compare the toll roads in the US to the toll roads in Mexico buisness wise since companies in Mexico and most of them are Spanish that have those "conseciones" do not publish any documents as to the operations.
Some of these Spanish companies may be using the toll roads as a tax shelter the more they loose the less tax they pay in Spain, remember that the Conquistadores introduced the MORDIDA to Latin America so maybe there are hidden agendas tnat we will never find out.
navegator