OS Highways Converter 2.01 (XML)

Ordnance Survey Highways Network is the next generation of official British maps.

RouteWare has developed a converter that makes most of the information from this dataset easily available to all of RouteWare's routing products.

The converter is supplied free of charge, if you have less than 5 MB of data to convert.

Otherwise it can be licensed for €300 from ShareIt.
See further licensing terms in the help file.

Starting from April 2024, licenses are valid for only 3 years, but includes both the XML and GeoPackage version, if you want to.

It can be downloaded from the download page.

For more simple use, the free OGR2OGR command line can be used for the translation, since fileformat is GML3.
What it won't do, includes at least turn restrictions, paths, change-only-updates, splitting loop links, ferries, attribute setup etc.