The number of cross-border travellers using rail services between Belfast and Dublin has plummeted since the collapse of the Malahide viaduct in August.
Figures supplied by the SDLP show a 60% fall in passenger numbers on the Enterprise service since August.
Bus transfers are still in place between Drogheda and Dublin on the main Belfast-Dublin route while repair work is carried out at the collapsed viaduct.
A 20-metre section of the bridge crumbled into Broadmeadow estuary two months ago just minutes after a passenger train had cross over the line.
The repairs are expected to be completed sometime next month.