Buses were often hijacked and used as burning barricades, and drivers were assaulted or robbed, while a total of 17 Ulsterbus and Citybus employees were killed over the course of The Troubles.

1,484 buses from both fleets were maliciously destroyed from 1964 to the signing of the Good Friday Agreement in 1998, with second-hand vehicles occasionally acquired from British operators.

[14] A Metro double-decker bus, which was operating on route 11b, was hijacked and set alight by sectarian rioters at the junction of Lanark Way and Shankill Road on 7 April 2021 during the 2021 Northern Ireland riots.

[15][16] Another Metro double-decker bus, which was operating on route 2e, was hijacked and set alight in Newtownabbey in County Antrim on 7 November 2021.

[17][18][19] As of 2021, Metro operates a fleet of 260 buses from four depots, namely Milewater, Newtownabbey, Falls Road and Short Strand[20] predominantly bodied by Wrightbus of Ballymena.

[22][23] No further double-decker buses were purchased following Citybus' integration into the NITHC, with high maintenance costs being cited for the move to single deckers.

[24] However, in 2001, double decker buses were reintroduced to Belfast through the purchase of 20 low-floor Volvo B7TLs with Alexander ALX400 bodywork for both Citybus and Ulsterbus.