When a tire explodes on the highway, two things happen: the vehicle begins to slow down and sway in one direction. Yes, you ultimately want to end up safely stopped in the shoulder, but first, you need keep control the vehicle to avoid swerving into another lane or grinding to a dangerously slow speed. That means you'll need to keep pressure on the accelerator – or potentially even step on it a bit – so that the vehicle maintains forward momentum. Meanwhile, steer in the opposite direction of the pulling: If the vehicle is pulling left, steer right. Once you've got the vehicle under control, you can pull over in a safe location.
Why You Shouldn't Brake In a Tire Blowout