Power
Railroad inspectors have an incredible amount of power compared to the size of the industry and how few of them there are at any given time. This is because every stinking one works for the United States of America's Federal Government's Executive Branch's Department of Transportation's Federal Railroad Administration. That's kind of like being the President's third cousin twice removed...only instead of blessing your marriage with an awkward toast, he's blessed your job with his authority.
With one check of the pen or click of the mouse, you can shut down entire sections of rail simply because of one loose screw (or maybe because of one guy with a screw loose). All work has to be done according to the specifications that you are on-site to enforce. If a company wants to send eighteen rail cars full of cow poop (an incredible fertilizer that can cause a horrible explosion), they have to let you know about it (source).
As you might guess, there's a lot of responsibility that goes with that power. The reason for all of this authority is to help you prevent and prepare for accidents and catastrophes as much as humanly possible, and then learn from them whenever they do occur. You can feel a little sense of entitlement if you want, but just remember that you're representing your employer, and no one wants to pay a jerk.