RER AOpened8 December 1977 (last extension in 1994)TechnicalLine length108.5 km (67.4 mi)Track gauge1,435 mm (4 ft 81⁄2 in) standard gauge

How fast does the Paris metro go?

Trains average 20 km/h (12.4 mph) with a maximum of 70 km/h (43 mph) on all but the automated driverless trains of Line 14, which average 40 km/h (25 mph) and reach 80 km/h (50 mph).

What is the difference between Metro and RER?

Overview. Paris Metro lines are identified by numbers: Lines 1 – 14 run primarily within the city limits. RER lines are identified by letters: Lines A, B, and C run from the city center to the suburbs and the Paris airports. … Travelling outside the city on the RER, requires a more expensive ticket.