Nervous around traffic

Hello everyone, Just wondering if anyone else had experienced their staff pup being nervous around traffic and how can I resolve this problem.
I cant really understand why he is as we made sure from 8 weeks he was exposed to all types of traffic and we live on a busy street but he is still scared and will cower back or go up onto the grass verge until the car has passed and then lunge forward like he is trying to chase it.
I've tried treats when the car is coming but he ignores them and we end up in knots with the lead lol.
I had an idea just wondering if anyone can recommend this... There is a little bit of green near our main road and i was thinking of having him on a long line and playing with his football (which he goes crazy for ) near the traffic so he ignores it do you think this will work as treats do not seem to.
any advice would be much appreciated.
 
thanks

I would think that play will make the traffic seem very normal. Just a little nervous of playing football near the traffic though (That's the Parent in me Sorry )

As long as there would be no way of him getting in the traffic or the ball getting in the traffic and causing an accident :/ But that might be an idea! Does he know "Watch me" or something similar? Maybe you could try stopping at the side of the road and trying to keep his attention as a sort of training distraction?
Is he bothered by stationery cars?

Hi Emma he isn't bothered with stationary cars its literally when he hears them coming he will turn around and cower then chase them that might be a good idea to try get him to look at me

The watch me command could work. Suki used to be scared of trains and we would do something similar and sometimes give her a bone somewhere near a train station and move a little closer each day so she would get used to it

I had a similar problem when it rains or the grounds been wet ruby doesnt like the sound of vehicles, ive found giving her a tennis ball takes her mind of it