The obstacle is money. Everything else is just static.
well - money and a long line of over-paid lawyers paid to fight it like they did with the Oregon Inlet bridge. It might come, but what year? 2040?
If there's no money to build the bridge, whether a theoretical design meets required specs and complies with the law really isn't relevant. Ironically, there could be no litigation and suits would result in easy dismissals if certain entities would stop trying to inflate value by advancing administrative aspect of a bridge they don't intend to build.
There's no shortage of legal work out there, and this isn't the lucrative kind. Compared to most types of litigation, it's pretty poor compensation. Most doing it are doing the work because they are true believers in their particular cause.
The interesting thing is why it would be worth promoting an unfunded bridge knowing that would necessarily trigger litigation about something not even remotely close to being built.
Public/Private partnerships are all the rage in highway construction these days. You'd be shocked to hear how many highways/Bridges are owned by foreign entities. They make their money back in tolls.
As far as litigation, don't forget where the legal fees came from in the fight for the Bonner Bridge Replacement project. Southern Environmental Law Center and The Defenders of Wildlife...Flush with cash from feel good donations.
Virginia has done several. The problem isn't that there isn't a public/private partnership theoretically possible, but that ten years into trying (they were working this angle when VA was doing several of its deals) they haven't yet been able to show the bridge would pass more year round traffic than the Wright Bridge does now, and at $25-30 per car (either one way, or a toll split each way). That was to break even on the 2018 projected construction cost. There are some private foreign entities that would fund a project, but not at that break even point, so they would either need that amount of cars per day at a higher cost per car, many more cars, or another larger state funding block.
Any of those options would mean becoming a day trip destination, which may or may not be what residents want long term.
It doesn't have the advantage of connecting two separate counties, which usually helps funding.