If you had to choose to work at UP or BNSF, which one would you choose? Why?
Ask yourself why you want to work for the railroad industry and in what positions. Decide where you might want to work for a railroad. Then apply to both companies and see which of them invites you to a hiring session. After BOTH companies make you a job offer the ask which company you might prefer to work for. So much depends on the location and the players involved it might be really hard to generalize between the two railroads. The players and the climate evolves all the time. What is the norm today will have changed within 5 yrs, will certainly have changed over the next 10 yrs and is totally unpredictable over a 30 yr career.
Despite all the hoopla about a shortage of railroad employees and all the RRs having to hire like gangbusters you just do not get to walk in and ask for a job and hire out that afternoon. It used to be that way but not any more. You will have to see what you might be offered before you need to make the carrier choice. If you want to be an engineer and they offer you a carman’s position, take what they offer, work hard at it and transfer to the conductor’s job after a year or so. You get good experience and the first shot at the new job when they open up.