Paris Metro Line 3bis is the shortest line of the Paris métro subway system. It is only 1.3 km (0.8 miles) long. The line was built at deep level which explains why the platforms at Pelleport and Saint-Fargeau stations can be reached only by elevator. Because of its limited length and traffic, the line is served with shortened three-car MF 67 trains.
The merger of line 3bis and line 7bis, connected through an existing rail tunnel and allowing the opening of a closed station (Haxo), is being studied. The resulting line would become Line 15.