S - M - L - XL icons in map

The icons shown on the map is now based on intensity.
from track.module:

      $intensite = $track->dzplus / ($track->length / 4);
      $intensite = ($intensite - 30) * (100 / 40);

Anyone knows how to make the icons shown based on a selectable track category/taxonomy?
apshalt=xl icon
gravel=l icon
singeltrack=m icon
etc..