The issue seems to be one of terminology. The questions on the exam (and thus topic of the course) appear to be about technical competence at a handful of skills highly specific to the railroad industry. That's fine and valuable, but its not what most people would describe as "economics". I wouldn't expect the skills taught in an "economics" class to be concerned with the specific price of shipping a very particular bill of goods on a very specific line on a very particular railroad. I wouldn't expect "economics" to mean the fine grain details of the practical engineering challenges in laying out track. I would expect "economics" to mean some sort of underlying analysis of railroad pricing and capital expenditure practices.