Whats the best way to fix a broken friendship?

Admit you are wrong for whatever you did to the person, and if the friendship is that great it will fix itself. 

Be honest and open to them. Apologize if you did something wrong. Leave the door open for them to talk to you when they're ready. Just let them trust you, and give it time. Don't rush it, because that could make it worse.

One thing you could do is offer to help them with things. Just don't do this too much, because you don't want to bother them

Iwould suggest the myers-briggs type indicator because the railroad unions are looking for which are focused introverts. the mbti was designed to provide a lot of information about what a person likes and what their personality based on the four-dimension scale. also for an employer it has been extremely to predict how an employee would act in a professional setting. this is what the railroad unions are looking for. they want the railroad workers to be focused and skillful to ensure the safety of everyone around them. but the other assessments don't match the criteria for the unions. like the measure disorder, emotions and self-esteem while the rorschach and tat tests are both projective tests that mainly measure someone’s personality. also, because this job is not easy, it is vital to make sure the employers are hiring the right people for the job.