A shiny, new rail transport section has been added to the article. It comes complete with the only assessment I've seen so far of the question that you started asking: to what degree does the 20th century avoidance of famines result from transport improvements (the opinion belongs to Jean Drèze, Sen's collaborator). Your note on taxation also deserves mention, as does the opium (and other cash crop) economy (although McAlpin suggests its impact on grain production is minor). The effect of pre-1870 railways is missing, but I don't think NPOV is violated by the new section. Check it out.