I suspect to get there in the first place you had to go around a barricade.
I'm not a lawyer and not planning on playing one but I'd suspect as long as your not being threatened and the road is blocked the prudent thing to do would be to wait it out.
If your vehicle was singled out and attacked with you inside, Oklahoma's Castle Doctrine pretty much spells out a persons rights. Your vehicle is considered an extension of your home so anyone illegally trying to enter it and attempting to remove someone from inside can be met with all force up to and including deadly force to defend yourself and others inside.
Carjackings fall into that description as well.