I think it all comes down to convenience. If there isn't a recycling bin around, chances are that people would just throw it into the nearest garbage bin. It might increase recycling habits by a little as the thought would be on the back of their minds, but I feel like it all comes down to accessibility of the bins.

O god. I remember seeing people who wouldn't hold on to their plastic bottles/pop cans when the recycle bin was just a few feet away. Ugh those people