Catch points (sometimes referred to as trap points) are a kind of turn-out usually positioned at the end of sidings to prevent rolling stock accidentally venturing onto the mainline without clearance.
There are different types of catch points, the most common of which has just one point blade and a very short run-off, they also come with double blades and with varying lengths of rail attached after the point to direct a runaway wagon to the safest location whether it be a sand trap or a designated siding.
In the UK, it is the law that all sidings must have catch points to derail or divert any wagons or coaches that are moving unintentionally before they reach the mainline. Catch points are available in model form in both 00 gauge and N gauge.