My 6 month old springer spaniel has never liked traffic and her dislike is getting worse. We have a desensitisation disc and she shows no reaction to that at all, so it appears to be the size of the vehicle rather than the noise. She is ok with most cars, but anything else causes a bad reaction, particularly lorries and buses. Sometimes she will lay on the pavement. Other times she will bolt on the end of the lead, the typical freeze or flight responses.
We live in the country, so it would be possible to avoid traffic for the rest of her life, but we did want a dog we could take anywhere and that is just not possible at the moment. Strangely, she loves going in the car and shows no concern about other traffic whilst travelling.
For her afternoon walk I have been taking her to fields reached by crossing a road. I hoped that she would get her reward for being brave at the curb, but it doesn't seem to be making a lot of difference. I would be grateful for other suggestions.