I would tell him that you are terrified for both the children's safety and his. If he cannot change his behaviors, he cannot drive the kids and you will find an alternate arrangement, even if it means that the family gives up something to pay for someone to do it. If the older child is reporting that he's swearing and out of control in front of all the kids, then I'd take that very seriously. That has to be scary on many levels for the kids.
FWIW, my SS has a terrible driving record (our insurance may drop him) and recently got another speeding ticket - this time for going 91. I decided that he cannot take his little sister anywhere, period, til he gets his act together. He can't borrow any of our cars, either. I would never forgive myself if I allowed it and something happened. SS said he didn't feel unsafe and DH read him the riot act about how his driving shows total disregard for anyone else on the road and for his passengers.
If your DH puts himself through a tree alone, that's sad and one thing. But if his behaviors take you and/or the kids and/or someone else with him, that's another. If you are so worried you want to call the cops, something has to change. If he is unwilling to change and/or get counseling for his anger issues (which I suspect are not limited to the car) and to deal with his disregard of you and your children, then there are much bigger issues than texting behind the wheel.