Waze has the ability to track what roads or bridges require a toll to cross. It even tracks which direction is the toll and free direction if that is the case.
Routes with tolls will include a "toll" indicator next to the route to make you aware of the toll.
If you prefer to have Waze only route you on roads that do not require a toll, you can turn on the option to Avoid toll roads.
To enable or disable the Avoid toll roads option, open the Menu >> Settings >> Navigation >> Avoid toll roads - ON or OFF
This feature is not fully implemented in all countries. If you can't see this option please check if it's available in your country: http://www.waze.com/forum/viewtopic.php?f=3&t=23318