The Nantes conurbation is crossed by several rivers, making transport connections in some areas problematic. For example, while tram route 2 provided an efficient link between the Tertre campus and the city centre, the link between the two banks of the river Erdre in the campus area was not good. The traditional fishing village of Trentemoult on the left bank of the Loire was not well connected with Nantes or with the public transport network in the nearest suburban town of Reze. Nor were there any direct links between the two banks for pedestrians and cyclists, who were obliged to use two bridges and cross Nantes Island.
It was therefore decided in the Urban Mobility Plan to open up these two isolated areas and to use the waterways for public transportation. The navibus on the river Erdre would provide a direct connection between the railway station and the university campus, while the navibus on the Loire was designed to link Trentemoult and the city centre and tram line 1 on the right bank.