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Map

Moving Around - Finding Bridges

The opening view is of the US with sized markers for counts of brigdes by state. As you zoom in the markers change to the county level, however this does not work for every county (resolving the county & state codes can be tricky). As you zoom in bridges will begin to display. If there are many in one spot/area a multi-colored 'cluster' marker will be displayed. Zooming in closer reveals the individual bridges. Most of the bridges are displayed as "counties" or 'clusters' until you zoom in closer. This grouping of bridges in large areas is limited for performance reasons. Clicking on a marker will display an infobox containing information about the bridge. Detailed data can be found for a bridge by clicking on the name in the infobox that appears after clicking on a marker.

Performance

Google maps (along with about any other web based map program) consumes a large amount of memory when faced with plotting as many points as usbridgemap.com does. With more than 600,000 bridges in the database and data request passing in and out, a newer PC along with a fast network connection helps greatly. Restarting your browser after long periods of use can help too.

Missing Data

It is quite possible that a bridge is missing from the map. The plotting of the markers depend on the information in the database. Which is produced from the Federal Highway Administration's National Bridge Inventory (NBI). This data is reported to them mostly from State Agencies. It is quite possible that some data has not been collected in the field. Also in some areas this program might have trouble for unknown reasons due to data varying. Work is in progess to resolve and improve the site and the way it presents the information in the best way.

Quick Zoom

The map will center when an area is doubled clicked. This is handy if you have a large view and want to zoom in quickly. Suppose you have a view of the entire nation and want to see bridges in the Las Vegas, NV area. Double click on Vegas and use the zoom slider on the left to jump/zoom in close on Vegas. This is quicker than moving long distances while the map is zoomed tight.

Tips

Use the F11 key to temporarily maximize the size of your web browser to see the most map area. Pressing F11 again will return it to the previous size.

Use the "Zoom in" link in the pop-up ballon for a well to center the map at that location and zoom in. Switch to satellite view and "Zoom in" again to really get a close look at a well.

Detailed well information is available by clicking a marker and then clicking the bridge name in the pop-up balloon.


Requirements

You must have javascript enabled in your browser for this site to work properly. Enabling bookmarks will also allow your settings to be saved between sessions.

Google Maps imposes some minimum requirements on the browser, which thus also apply to this site. Currently supported are IE 6.0+, Firefox 0.8+, Safari doesn't seem to work, Netscape 7.1+, Mozilla 1.4+, and Opera 8.02+. IE 5.0 is not supported. Also, this site obviously uses lots and lots of images and data. It is really slow over dial-up.