I've been doing something similar with Galen this week. He seems to be in the thick of a fear stage: my previously bold little fellow is getting nervous about vehicle noises. On a nice warm day I grabbed a pocketful of treats and took him up to the busy state road near me. We plopped down on the sidewalk and just watched traffic go by. We saw joggers, bicycles, other dogs, motorcycles, lots of cars, and plenty of other traffic.
The big trucks were especially scary when they were jake braking. At first Galen was nervous and crawled onto my lap. I cuddled him and fed him treats until he relaxed. Then I started watching for trucks in the distance. As soon as I spotted one I started handing Galen treats and kept the treats coming until after the truck had roared past.
Today we went back to the same spot for more traffic watching. I was very pleased to notice Galen was much less concerned about vehicles. Instead he wanted those treats. We practiced an exercise you recommended, lily cd re. I held the treat in my fist until he stopped gnawing at me. Then, like magic, the treat appeared.
The magic continued. Whenever he flopped down in utter boredom a treat would mysteriously appear between his front paws.