Simplest answer is you start by giving these dogs the attention, exercise, and mental stimulation they need. The alternative is two out of control dogs that will fall victim to that old excuse "I can't keep them because they are too hyper". You can buy tons of books on dog training, but the reality is that someone has to actually work with the dogs, consistently and frequently.
They jump, bark and run into the street when off leash because they are full of energy that is not getting any other outlet. They are not looking to their owners to provide them with that outlet, so they find their own methods. Back country road or not, there are dangers out there.
Livin in a Newfie Drool Zone