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= Left- and right-hand traffic =
JOSM has an internal database of areas with left-hand traffic. This was added in version r7193. This is used in some [[Styles/|Styles]] for correct display. Examples are the default internal mappaint style (for cycleway lanes and tracks on highways or roundabout icons) or [[Styles/Maxspeed]] (for maxspeed:forward and maxspeed:backward). It is also used for the create circle action, to use the correct way direction, if you create a roundabout (r8303).

You can download the data [http://josm.openstreetmap.de/browser/josm/trunk/data/left-right-hand-traffic.osm here] (click on ''Original format'' on the bottom of the page) and load the file in JOSM to investigate the borders. The areas in the file describe the areas with left-hand traffic. All other areas use right-hand traffic.

You can use the pseudo classes `:righthandtraffic` for right-hand traffic and `!:righthandtraffic` for left-hand traffic in your mapcss mappaint style. See [[Help/Styles/MapCSSImplementation]] for more information. Note that you maybe get wrong results near to borders of countries with different driving directions since the area borders of left-hand traffic are simplified in JOSM. These simplifications are necessary to reduce the size of the database, but it can be refined on request.

If you notice an error in the database you can create a new ticket by clicking in JOSM menu Help → [[Image(source:trunk/images/bug.png,20px,middle)]] [wiki:Help/Action/ReportBug Report bug].

Screenshot of the areas with left-hand traffic:

[[Image(leftrighthandtraffic.png)]]

^(data used for image [osmwww:copyright ©OpenStreetMap contributors] ODbL, tiles: Mapnik CC BY-SA) ^