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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.

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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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