20-Year Prospect
If you were to shake one of those totally legitimate and not-at-all-waste-of-money Magic 8-Balls and ask "Will railroad inspector be a career in twenty years?" the answer would be "Hazy, ask again." According to labor statistics, railroad occupations in general are falling and don't look like they're coming back any time soon (source).
Also, unlike Europe or China, who are developing the electric, high-speed, and maglev trains of the future, the United States doesn't really look at railroads as something it wants anymore (source). However, that doesn't mean the U.S. won't eventually join the rest of the world and invest in a 21st-century rail system―we're just not going to be placing any bets any time soon.