That's so weird: nobody uses miles in Italy (or Europe, except the UK). I checked the article and the source is Strava Insight which probably defaults to miles. The journalist copied and pasted without converting the units into something readers would understand.

14.8 miles per hour is 23,68. I usually do 20 when I move in the city because I don't want to sweat and I don't see many bikers going faster than me. Maybe that's because only fast bikers use Strava and it skews distances and speeds.