Not sure if it would grow in your zone but I have recently planted creeping Jenny and fine it to be a good edition.
Engi

I've just planted Corsican mint. It's recommended for between pavers and is hardy zones 6-9, but likes it moist.

I found this on the California forum.

"My favorite lawn substitute for full sun is a low-water groundcover from So. Africa called Dymondia. Here in So. Calif. you can grow it very successfully with virtually NO care once established. You can walk on it, park your cars on it (we planted it in our gravel driveway), snails and slugs pretty much ignore it, and even the rabbits can't kill it. I used it between stepping stones, too, and because it never gets over about 1" high it works great."

Golly, I thought I had found someone in my zone but as you can see anything I suggest would be all wrong for you.
Don't you wish someone would figure out how to seperate our Zone designations.
I hope you got some help.
Just in case you pathway is relatively dry I have used creeping Thyme with great success both here in Florida and upon Long Island in New York. Find the seeds and scatter them where you want plants (rather thickly) and have a little patience.
Smells wonderful when walked on but cannot take heavy traffic.
Sandy