The recommended way to help a dog over a fear is to grasdually approach the frightening situation while the dog is in a positive headspace.
Preparation
Choose a game your dog loves most, like fetch, tug of war or abort.
If your dog doesn't like to play that much, you could wake his interest in a prey dummy or tread pouch that is filled with treats. First let your dog eat from the pouch, then throw it a few meters (can be done indoors) and let him take a treat from the pouch when he brings it back to you. If he doesn't bring it to you at first, let him make the experience that he cannot open the pouch on his own, but don't let him walk away and destroy the pouch. He must learn and understand that fetching the pouch means he gets a treat, but that only you can open the pouch to get the treat.
Train this game for about a week until your dog understands the rules and has fun playing it.
Desensitization
Start playing the game in an environment where your dog feels safe. This could be your living room, your yard or garden. Play with him for a minute or two, then slowly and gradually move the game towards the environment where he doesn't feel safe anymore. Stop as soon as your dog gets nervous or distracted by the street and take a step back into the safe territory, continnue playing for 5 - 15 minutes.
At first, it's enough to move from the living room to the front door, from the back of the garden to the front gate. Don't overdo it and be happy for every small step your dog takes. Repeat this training for another week or more if your dog still shows clear signs of fear when approaching the street.
Then start stepping out of your "home territory" into "street territory". Put your dog on a leash for safety, but continnue playing with him like before. Start playing at home, then move out onto the side walk. It will probably take another week or two until your dog looses his fear.