Air travel is also heavily subsidized, and road travel even more so. One of the real reasons for the interstate highway system (not the purported reason -- defense -- that got the bill through Congress) was to break the back of the rail monopolists (and, importantly, the rail unions). The American state chose to literally invent a whole new kind of socialized transport (marketed as a form of consumer individualism) than just nationalize and upgrade the railroads like every other civilized country.