Here you find the official download of the railTopoModel versions as well the UIC's IRS 30100 standars.
IRS 30100 (railTopoModel V 1.0) (4.2 MiB)
railTopoModel V 1.1 (as of 6th of November, 2017) (771.3 KiB)
railTopoModel V 1.2 (as of 29th of August, 2018) (1.5 MiB)
railTopoModel V 1.4 (as of 29th of April, 2022) (1.4 MiB)