The Harmelen train disaster, on 8 January 1962, was the worst railway accident in the history of the Netherlands. Harmelen, in the central Netherlands, is the location of a railway junction where a branch to Amsterdam leaves the Rotterdam to Utrecht line. It is common at high-speed junctions to avoid the use of diamond crossings wherever possible – instead a ladder crossing is employed where trains destined for the branch line cross over to the track normally employed for trains travelling in the opposite direction for a short distance before taking the branch line.

Automatische TreinBeïnvloeding or ATB is a Dutch train protection system first developed in the 1950s. Its installation was spurred by the Harmelen train disaster of 1962.