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What is a dynamic map
A dynamic map is a map that allows users to interact with and see geographic
features on a digital map. In contrast, a static map is generally created by a
cartographer or graphic artist and the content or appearance of the saved map
file cannot be changed dynamically through interaction by a website user.
In a dynamic map, the website user can change map scales and zoom levels, and
even select or place new map features, in some applications. Additional
geographic features become visible as the user zooms further into the map. In a
dynamic map environment, it is also possible to separate map data layers, and
turn the visibility of map layers on and off.
Using a map to specify your origin or destination
The dynamic map window in the application allows the user to select a origin
and destination directly from a map using this website. Why would users want to
do this? Because sometimes other means of specifying a location (e.g., entering
a street address, intersection address, or landmark) may not work adequately
(for more information, please see the main help menu section for the
application called: Why origin or destination address may not be found?).
How to interact with a map interface
This dynamic map is initially displayed with the extent of the entire Bay Area.
Map functions available on other types of interactive maps on this website are
also available on this dynamic map. These include zoom in/zoom out, pan,
display an inset map and legend, and centering the map to a desired location.
These map functionalities are described below:
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Zoom In/Zoom Out
- There are 9 (nine) levels of zoom in/out provided through the nine round
buttons below the map. Clicking on these buttons will allow the user to zoom in
for more detailed information about streets and other map features, or to zoom
out to see a wider view of the area. These buttons enable the user to zoom in
or out from the center point of the map currently displayed.
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Pan Tool
- There are 8 (eight) triangular pan buttons placed on the border around the
map. These pan buttons are very handy for shifting the map around. Click the
triangular pan buttons around the map border to shift the map in the direction
that the triangular button points.
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Legend
- The 'Legend' link allows users to see the legend for data layers in the map
(such as roads, highways, parks, lakes, etc.). When clicked, the legend link
removes the map and displays the legend. Clicking on 'Return to the map' from
the page displaying the legend will take you back to the map.
Additional interactive map tools on the dynamic map.
In addition to the regular map interaction features described above, this
dynamic map interface includes a few additional features described below. These
are activated via the four rectangular graphic icons located below the round
zoom in/out buttons. The currently selected rectangular icon will be
highlighted in a different color than the other three. The active graphic
icon is always highlighted. The 'rubber band box' zoom icon is
selected by default when you first open the dynamic map window.
These graphic icons are described below, as they appear from left to right in
the dynamic map window (the names of these icons will also appear in the lower
left hand corner of the dynamic map window as you scroll over them with your
mouse cursor):
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The Map Centering icon
- (first rectangular graphic icon from the left, above the Map Legend link) can
be selected with your mouse, then click on the map to center it in the desired
location.
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Inset Map icon
- The inset map function is activated using the second rectangular graphic icon
from the left. It will display a smaller map showing the location of the
zoomed-in area relative to the entire Bay Area. This can be helpful to maintain
awareness of where you are zoomed into within the Bay Area region.
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To turn the inset map 'ON', click on the inset map rectangular icon. To turn
the inset map 'OFF', click on this icon when the inset map is displayed at the
upper right corner of the map frame.
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Rubber Band Box zoom icon
- The second graphic icon from the right side provides a more flexible zoom-in
feature. Users can select this icon and draw a rectangle on the map to define
the zoom-in area.
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To use this rectangular zoom box, first click on the icon. Next, move the
cursor to one corner of your desired rectangle for zooming into while holding
the mouse button down. Then drag the mouse to the diagonally opposite corner of
your rectangle and release the mouse button. Within a few moments both main map
and inset map (if that is turned 'ON') will be redrawn showing the extent
defined by the rectangle.
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