.bicycle_parking{
  [zoom <= 15] {}
  [zoom = 16] {point-file: url(res/maki/bicycle-12.png);}
  [zoom >= 17] {point-file: url(res/maki/bicycle-18.png);} 
  [zoom >= 19] {point-file: url(res/maki/bicycle-24.png);} 
}
