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.

A double junction is a railway junction where a double-track railway splits into two double track lines. Usually, one line is the main line and carries traffic through the junction at normal speed, while the other track is a branch line that carries traffic through the junction at reduced speed.