This happened despite the tracks having the latest safety features available at the time: a system of interlocking should have made it impossible to give clear signals to trains unless the route to be used is proved to be safe.
In his book L. T. C. Rolt comments that "Scarcely any safety device existing at the time was lacking on the network of lines outside Paragon station..." - however, one safety device did exist and was lacking - a track circuit which had been invented in the USA in the 1870s and began to be used in the UK from the beginning of the 20th century.
In his report on the accident, Col. J. W. Pringle recommended installation of a track circuit, which the LNER then carried out.
Three signalmen were present in the signalbox, the enquiry found that one of them had pulled the wrong lever; he had intended to set the points for the incoming train but instead set the points ahead of the Scarborough.
The points were locked and could not be moved as long as the signal ahead of the Scarborough train was at clear, and also by the presence of locomotive or vehicle wheels on the locking bar immediately in rear of the points.