I took my car down on the Auto Train last year, then drove to Miami Beach and drove around the greater Miami area a bit. I agree that the traffic has gotten worse (than my last trip in 2015), but it was bad then, too. What I noticed was a sizeable minority of drivers making knucklehead maneuvers, excessive speeding, disregard of traffic controls, etc. That in addition to the congestion. At first, I thought it was a "Florida Man" phenomenon, then we returned home, and I'm seeing similar stunts on the road in Maryland. I suspect it's a mental health issue wrapped up in the lingering recovery from the Covid pandemic.It'll be 30 years I've been living here and here is my take. The roads now have gotten worse then when I first moved here. Problem is FDOT has to bare the blame. Look at how many accidents and wrong way incidents have happened on I-4, after the I-4 Ultimate project completed.
FDOT will not fund such a project to remove grade crossings on the Brightline corridor, because they simply don't want too. They don't have a serious plan to address congestion on Florida's roads either, other then to add more lanes of highways. Look at the state of public transportation in each county in Florida that has transit, and ask yourselves, if that's a serious way to provide relief from the congestion on Florida's roads.
As for the traffic congestion, there's nothing one can do, except getting people out of their cars, but that means getting rid of suburban sprawl, which has a much of a chance of happening as a Communist candidate winning the next presidential election. I'm not sure Florida is any worse than Maryland or Virginia in this regard.
It's not clear to me exactly who funded the removal of the grade crossings on the NEC South in the early 1980s, nut I suspect it was taxpayer money of some sort or another. I would seem to me that one task for Florida's representative and senators in Washington is to get a nice little pork-barrel project funding grade crossing elimination on this stretch of track. If they have problems with giving taxpayer money to a private corporation like FEC, then they can fund the local highway departments to build road bridges over the tracks.
But, thinking more, maybe this is a Florida thing. Back in circa 1975, they were running frequent passenger trains on the NEC at 90+ mph (Metroliners did 110), commuter trains, and even freight, there were grade crossings, there must have been crashes, but I really don't remember them being that frequent.