It's tough to compete with the price of taxis in Tunis if your time is worth anything--but if you're traveling with a group of 3+ adults (more than a taxi is allowed to take) you might want to know how the bus system works.

This website helps you figure out the system according to:

-destination

-station

-line

It even tells you the costs AND gives you a place to complain if you have a bad experience!