NJ Transit employees advancement questions?

I just wanted to ask a quick question NJ Transit employees. I see that NJT is hiring for bus fuelers/serviceperson and I'm gonna send my app. in and resume tomorrow. What kind of advancement is there from there and is it easy to o so? Can you go from the bus side to the rail side easy or is it hard? Can I eventually go into the track department from this job? I think I heard you have to be in the current position fr a year before moving on, and I'm ok with that. Thank you for any info you mayt have. I already have CDL class A by the way.