That used to be the case in Ireland too, but confusion due to cultural contamination means pretty much everyone moved to numbering lanes (from the "outside"/"slow"/leftmost lane).
When I did my B license test probably about 30 years ago, the Rules of the Road all referenced inside/outside lanes. When I did my CE license last year, it had been updated to only use lanes 1, 2, 3 etc.
Obviously fast and slow are just colloquial terms.
