With respect to the RR in Panama: Yes, it was the first (by ~14 years) to connect the Atlantic and Pacific oceans, but to call the 50 or so miles between them a continent - and therefore the RR a transcontinental one - is stretching the meaning of words too far.

I had an adventure hiking the nearly abandoned RR about a decade ago, from urban slums through jungle grass several feet high, across long bridges, by native villages, and finally to the urban slums at the other end. High point of the trip was being thrown into prison for intruding into a "natinal security area". I wrote up my trip, and I'd be happy to email a copy to anyone who posts an email address.

Best regards to all, Chuck Lee.