There are four conventional metro lines and, , 59 stations (not including "premetro" stations). Most stations are underground, although some on lines 5 and 6 are at ground level. On 4 April 2009, the connection at Gare de l'Ouest/Weststation that enables line 2 to form a circular line was put into service. As a consequence, the metro network was significantly reorganised. The development plan for this change and related tram and bus network changes was approved by the Brussels Capital Region in July 2005.