Why not the opposite?

There are almost zero carpools from where I am to other places.
I would like to see an option to, instead of accept or deny a carpool from someone, I could suggest that I would like to go somewhere.
Once people see that more people want this carpool they can arrange one!

Naoseioquebotaraqui about BlaBlaCar: Carpooling and Bus, v4.9.8