[mkgmap-dev] Style rule for dual carriageways

Wed Jan 18 16:38:03 GMT 2012

I tried to make a map with an extra style for dual carriageways for each 
of highway=primary, secondary, and tertiary. The problem is that I do 
not see an appropriate tag to search for. Dual carriageways are 
characterized by two roughly parallel ways with oneway=yes. It is not 
necessary that they are tagged with highway=trunk.
highway=tertiary & oneway=yes  {set highway=tertiary_dual;}
often does the trick, but it changes also some other roads.
Do you have some better suggestions?