They do normally do road safety in schools around this age but suspect its another thing that has been knocked on the head at the moment. I volunteered for this - felt like it was a family tradition as My Dad was the ouncil guy for where we lived for the tufty club and the green crossed code man.
Basically you walk with the children holding hands, and hazard spot - so you do parking areas and parked cars - what to listen for exhaust pipes, engines, revving, indicators when they flash with someone opening a car, how to keep away from doors that might open, get them to sit in cars and see if they can see other kids in the mirrors when they are around the car, the height of wing mirrors which is why they should stay well back from the curb etc . We talk to them about break lights and so on and how they know if a car is on or off and which direction its travelling (so reversing lights)
Then on the road - we went to a busy rd supposedly a 40 and measured speeds to show childrren how drivers ignore the rules and create danger, we spot drivers eating, on the phone, with lots of people in cars and the same for lorries - and beign busy the noise hits them as well standing there for a short time (well back from the actual road an again holding onto the kids etc) we explain why running on a road is a no no - in case of falls and also the speed of movement means a driver doesn't have time to react etc, the importance of using crossing points and if there are none then how to pick a safe spot but also what is the safest way (ie an adult accompanying and holding hands).
For me your Son doesn't sound old enough to cross himself and needs to stay with you still either holding onto pram or a chain of handhlding (you could sell it as teaching a younger sibling to be safe etc)
Te driving on todays road - volume of cars as well as behaviour, means for the most part it is not safe until much older - I am afraid I see kids 11 to 16 also being ridiculous on bikes etc and not understanding the life changing things that can happen. People think we should shelter children from accident outcomes but I am afraid I don't think we shuld - they take far too many risks and treat it as a video game where thy just have to wait for another life to pop up