Every social networking website increase the traffic but you should have huge amount in friends ( followers ,circle) etc.So your site will visibility fast.
I don't believe that only G+ can increase your traffic. You should participate other Social Networking websites to increase traffic.
to increase your website's traffic via google+ there is only way is: more people should add you to their circles / you have more people on your circles then only you posted website update can reach more people so more people may visit your site/page.