To make this clearer, I'm going to use the the word "section" to mean a length of road between two junctions/intersections.

I think it is true that osm2po (under default user options) creates a graph in which a section is sometimes made up of more than one link. I'd like to ask if it is possible to make each link equivalent to a section, either using osm2po or using a simple post-processing step.

It seems obvious that a simplified graph would be quicker to use in routing and would also correspond more neatly to other data sources (such as traffic information)

Thank you, in advance.


osm2po does not simplify the underlying OSM-data. And in my opinion it is not necessary. Your problem only refers to very long roads which are rather rare. Usually even long roads may change between source and target; think of speed limits, grades, pavements. There are tons of attributes which split an obviously complete way into sections. And if there are no differences, it's never a good idea to draw a 10km long road in one piece into OSM-Josm. This would result in ways with thousands of geometry points, sth. that is not wanted - for editable and technical reasons. No, I do not think, that the Graph size blows up or the routing slows down dramatically. And there is another issue: Once having simplified e.g. 3 osm-ways into one single section you'll lose the origin, namely the original way-ID.

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  • OK, thanks for a great answer. I follow the reasoning which I had not thought of before. osm2po is a great product to use. – John Steedman May 11 '13 at 9:05

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