Since 2000, the variety of species alongside motorway verges has increased further. It mainly concerns an increase in widespread species, but there is also an increase in rare species. The diversity of the flora found alongside provincial and municipal roads has remained more or less the same.
Verges alongside motorways are mown only once or twice a year and not before mid-June, when most seeds are already ripe. The mown vegetation is subsequently removed and the soil gradually becomes poorer in nutrients. As a result, the roadside flora has become richer and more diverse.
Floral diversity roadside verges, 2004–2006