Rail is very expensive to build and will be very expensive to ride.  It will serve a small group of people, but it won't serve the masses.  I had hoped to use mass trans when I reached 70, but my experience has shown mass trans is not for me.  I live in old Ewa, so I have to walk a bit to the bus stop.  Walking is not a problem since I go on a very brisk, sweaty walk every evening with 3 dogs weighing 5 to 45 lbs--needless to say, the 5 pounder has to be carried as the big dogs outpace him. 
I needed to take a few different busses to get to the dentist in Wahiawa.  One wrong bus (the numbers on the bus don't change, but their direction does) and I ended up going to Waianae, so the bus driver put me out next to a field of kiawe bushes.  The next bus took me to Dilingham near the prison.  I was 2.5 hours late for my dental appointment.  So, getting to the rail may be a problem, your final destination may be another probllem.  I'd rather use my time and money on alternative trans.