How long have you had her and how soon did you start exposing her to traffic and other things? It is vitally important that dogs are exposed to as much as possible in the period between 6 and 12 weeks. Before 6 weeks they won't pay much attention to anything except the mother and litter mates. After 12 weeks, much of their personality is set and is difficult to change. Too many puppies spend that important time in a kennel or a pet store cage.
You should be able to work with her, although it will be slow and difficult. Start with obedience training. The key to most behavior problems is approaching things using the dog's natural instincts. Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog. Life is much easier if the 2 legged pack members outrank the 4 legged ones. You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at
Raising Your Dog with the Monks of New Skete As you praise the dog for following your commands, it will build its confidence.
Play tug of war with the dog and lose. However at the end of the game, take the rope or toy and put it up, less the dog becomes confused about who is top dog. Ropes from the pets' store quickly turn to hazardous shreds. Ones I made lasted much better. Go to a hardware or home center that sells rope by the foot. Buy 2' of 3/4" poly rope. Melt the ends, and tie knots in it. Get them as tight as possible, put it in a vise and pound it with a hammer. Watch carefully, and be ready to discard when it comes apart.
Finally, make sure it has a den to live in. If you are not using a crate, buy one. The dog may be happier in its den than loose in the house. It relaxes, it feels safe in its den. It rests, the body slows down reducing the need for water and relieving its self. Dogs that have been crated all along do very well. Many of them will rest in their crates even when the door is open. I think the plastic ones give the dog more of a safe, enclosed den feeling. Metal ones can be put in a corner or covered with something the dog can't pull in and chew. Select a crate just big enough for the full grown dog to stretch out in.
A dog that has not been crated since it was little, may take some work.
Start just putting its toys and treats in the crate. Praise it for going
in. Feed it in the crate. This is also an easy way to maintain order at
Feeding time for more than one dog.
Continue to expose her to traffic, but don't overwhelm her. Find a park or other place near a busy street where you can start back a ways and work your way closer to it. Be calm and confident yourself. Our emotions flow straight down the leash to the dog. No high pitched ''Poor little doggy woggie''. That only rewards her for showing fear. Instead, praise her as she accepts approaching the traffic. I can't think how to apply the technique of going up to whatever the dog is afraid of and patting it and talking to it, to the traffic. I never applied it with the one dog that was afraid of women in broom stick skirts either.