Templot is a free, downloadable computer program written by Martyn Wynne for designing model railway track, which uses design parameters from prototype practice. The program can be used to generate construction templates for turnouts, crossings etc. as extracts from a complete track plan of a model railway.
The website is found here:- http://www.templot.com/
Pictured:- A storage yard for a layout, designed using Templot:-