Budapest Transport Company (BKV) and Alstom signed a contract in 2006 for 22 five-car trains for Line 2 and 15 driverless four-car metro sets for the new Line 4. In October 2010, BKV cancelled the contract after NKH denied type approval on the grounds that the braking system did not meet Hungarian standards. Alstom argued that the trains had been accepted elsewhere in Europe and refused to change the design.
However, Alstom and the Mayor of Budapest later reached an agreement stipulating that the contract could be revived if Alstom agreed to reconfigure the trains to meet Hungarian standards, and obtained type approval within 300 days. This amended contract was signed in August 2011 and the type authorisation documents were issued six days before the deadline.
The three prototype trains travelled a total of 35,000km during this time, (partly on the test track at Valenciennes in France) including 4000km of fault-free running on Line 2.
Alstom will now deliver three sets per month and the first new trains may enter service after individual approval in September 2012. All 22 sets have now been assembled, although some still await modifications.
NKH will soon grant type approval for the driverless trains ordered by BKV for Line 4, although testing will not begin until later this year because trackwork is not yet complete on the new line.
