Although this line is still as a diversion if HSL1 is doing engineering, also depending where the maintenance is taking place.[2] Journey times between London and Brussels were improved when an 88-kilometre (55 mi) Belgian high-speed line, HSL 1, opened on 14 December 1997.[64][65] It links with LGV Nord on the border with France, allowing Eurostar trains heading to Brussels to make the transition between the two without having to reduce speed.