I agree with the previous comment! Keep treats on you and slowly coach her outside. She will get used to the noise eventually, just like humans have to! But for now, I would make her go outside when they expressway isn't as loud. Distraction is the key! Anything that will keep her focused on what YOU have instead of the trucks. Try using squeekers, clickers, praise is always a good distraction as well. Hope this helps! Good luck.