Here's a suggestion about the litter box. We have a cat door out into the garage where we keep the litter box; then the smell at least is not inside your house.

If your cat is an indoor cat, you need to check on them before you open the garage door to make sure you don't startle them and make them run outside.

I have cats that were outside and inside cats. But, we have never lived on a busy street. One lived till he was 17 (had a heart attack) and the other is still hanging in there at 23. This garage cat litter box has always worked fine for us.