Social stories and repetition. Tons of cute characters teach kids about traffic safety. Robocar Poli has several safety videos on Tubi that are free to watch. Pinkfong also has traffic and other safety videos.

Theres a great animated video for kids with a song about street safety. I'll try to find it.
https://do2learn.com/games/songs/streetsafety/s...

I held my son's hand to cross the street until he was a teen and he was okay with that. He too would just cross without thinking or looking.

This is one we have a hard time with, too. My kiddo just doesn’t see the danger. I try to tell him before we even get to the parking lot or crosswalk or street that we need to watch for cars, and then remind him again when we are actually crossing the street or whatever. Sometimes that helps and sometimes he’s just bouncing all over the place and darting out no matter what. It’s a tough one, but I agree with what others have already said, it just takes more and more practice. Good luck. And go Giants!!

Just by watching others at traffic signals using signals correctly or watching you but it means you have to keep taking routes to practice