gistfile1.txt

  #commutetime [Workers > 50000] {
  marker-width:3;
  marker-fill:#efc635;
  marker-line-color:#efc635;
  marker-allow-overlap:true;
  marker-opacity:.5;
  
  [TravelMins > 0 ] { marker-width:1; }
  [TravelMins > 20 ] { marker-width:2; }
  [TravelMins > 23 ] { marker-width:3; }
  [TravelMins > 27 ] { marker-width:5; }
  [TravelMins > 30 ] { marker-width:10; }
  [TravelMins > 35 ] { marker-width:15; }
  }
}