Opened on 15 March 2002, the metro in Rennes is based on Siemens Transportation Systems VAL (véhicule automatique léger or light automatic vehicle) technology. There is only one line, the 9.4-km a Line, which runs north-west to south-east from J.F. Kennedy to La Poterie via Gare de Rennes (served by Gares metro station), with fifteen stations, thirteen of which are underground. The station at La Poterie and viaducts on the line were designed by Norman Foster.

The network is run at any time by at least four people at the central command post (poste de commande centralisée) situated near the Chantepie yards. 120 cameras patrol in and around the stations on the line.

Services run between 05:20 and 00:40 every day of the week, and trains come between every 3 and 7 minutes. From end to end, it takes around 16 minutes, with an average train speed of 32 km/h. All stations are equipped with lifts.

The system has sixteen trains, weighing 28 tonnes and 26 metres long, which run on two tracks next to each other. Each train has a capacity of 158 passengers (50 sitting and 108 standing). In 2005, four extra trains were added, and four more will enter service at the start of 2006, leading to waiting times of only 90 seconds.

Excluding the minuscule underground network of Serfaus, and until the opening of the metro of Lausanne in 2008, Rennes is the smallest city in the world to boast a metro, with a population of just 220,000. On average, there are 110,000 metro trips each day; this figure is expected to rise to 150,000 in coming years, leading to possible gridlock during the rush hours.

In January 2005, three park-and-ride lots were set up, offering 900 places to motorists. Two more are under construction, expected to park an extra 700 by 2006.

On 1 March 2006, a card called KorriGo was created as a supplement to the ticket system to improve the metro traffic and the city's bus network.

The line is maintained by STAR (Société des Transports d'Agglomeration Rennais), and managed by Keolis (an SNCF group). It is staffed by approximately 100 technicians, managers, and so on.

A second line, the B Line, with an orientation northeast to southwest, is scheduled for 2015.