4 year old still doesn’t understand street safety

I’ve tried everything short of telling her that if she gets hit by a car she will die, but she probably wouldn’t understand that either. She’s on the spectrum but we’re still waiting for an actual evaluation. She starts school next Monday and since we don’t have anything formally diagnosed she will be in general classes and treated just like the other kids. That means recess nearby a busy road and nature walks, etc. I’ve talked to the teachers and they can’t just keep her out of it and I don’t want that either but I’m terrified she will slip away and run for the road or try to “go home” because she knows directions pretty well and we are just a block from the school.

Is it common for children to have no regard for road safety at this age? I’ve been working with her since she could walk. How do I do this because I’m scared honestly. My husband thinks I’m overreacting but I don’t think my kids safety is an overreaction