For more information regarding measured ambient air quality levels and California ambient air quality data, go to ARB's Air Quality Data web page. In order to make the map screen more visually useful, the number of mapped roads is based on the current scale of the map. A threshold is set so that fewer highways and streets are labelled when viewing a large area. If the administrative boundary is small, or the zoom in map click function is used, the number of labeled roads displayed on the screen increases. The location of the buttons to enable these functions are located to the right of the map screen.
Buttons are only available when that action that they take is appropriate.
To use a map click function, click on the small circle to the left of the function's caption, then position the mouse pointer over the area of interest on the map screen and press the left mouse button one time. This operation submits the parameters set on the screen, as well as performs the map click function that was selected. To zoom farther, choose a larger zoom factor. Next, position the mouse pointer over where you would like the new map screen to be centered, then press the left mouse button. The map screen will zoom based on the zoom type, zoom factor, and map position that you chose.