text: var windowWidth  = window.innerWidth;
  var windowHeight = window.innerHeight;
  
  var simulationCanvas = new Canvas(
      "ShowSimulationCanvas", 
      windowWidth * 5 / 10, windowWidth * 5 / 10, 
      "rgb(200, 200, 200)", 
      true, 
      "rgb(150, 150, 150)"
  );
  
  var showTrafficLightCanvas = new Canvas(
      "ShowTrafficStateCanvas", 
      windowWidth * 3 / 10, windowWidth * 5 / 10,
      "rgb(200, 200, 200)",
      true,
      "rgb(150, 150, 150)"
  );