Mattius,
The one chink in the armor about Commuter Rail is that it first relies on Downtown Jax being the only hub.
Yes, this makes logical sense, and would work for most of Jacksonville.
There is however, a huge portion of Clay that commutes to the Southside.
You will not get buy in from that crowd until there is a direct route between points in Clay and the Southside of Jax without having to go through downtown first.
If you want to tie commuter rail in with the Amtrak/FEC line, it still wouldn't attract that many people from Clay to downtown Jax. Most would drive to St Augustine and use that facility.
I say build the outer beltway, a good portion is already done/started. And yes, it does help relieve congestion (although a bridge in Fleming Island is a much better idea than GCS)
Add a commuter line down the middle of it, this will attract more ridership from Clay than the route through downtown would.
Trust me, this is what helped slap JTA in the face over BRT. You cannot expect people to take longer to commute by bus or rail than they do by car. My commute is 45 minutes each morning, it would take over an hour using Commuter Rail. Not only do I save 1/2 hour each day, I also have my car with me. Is it worth the extra 30 minutes a day, and loss of car use if needed for work, and being stuck to a schedule for a few dollars a day savings in gas?
You have to hit home on time/cost/speed.