You can take a share taxi from Tunis for under 10TD 4.750TD per person, december 2011. These arrive to the south of town - from there, either get a taxi or simply walk a few kilometers down the main road and over the modern suspension bridge in to Bizerte proper.
Its also possible to get in by louage from the west, eg: Tabarka, though this may require changing a few times en-route.
