Hi Felix, attached is a patch that may help to solve your problems with reversed oneways. It may not work without --ignore-turn-restrictions. I'd first like to make sure that I understand what you are doing. I've added a few lines to the default style to produce additional lines for ways with highway=* & incline=up If I got you right, you create one oneway for the uphill direction and another one with reverse direction for downhill, and also overlaying lines with types that are direction dependent. The result is in switch_oneway.zip. The attached reverse-oneway-v3.patch changes mkgmap to keep the order of points in each way. That means, points are reversed after style processing if tag oneway=-1 is found, and this order is then maintained in the rest of the program. Gerd P.S. I think we can drop the idea of reversing ways with "oneway=-1" before style processing. This will not help in your case, as you add the tag in the style.