New answers tagged road
Ok a lot of questions, so I will start with a general hint: What you are looking for is just a 'routing graph' for a geodata set (here: OSM). As you say this graph needs to fullfil certain properties (as connectivitiy, level of detail, ...) but IMHO your cell approach sounds a bit complicated. There are existing solutions to turn OSM raw data into graph ...
It's possible to have a resolution or precision problem (zoom). Check your snap in ArcGIS Desktop : http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Snap/001v00000007000000/ Use the improved Feature Editing (Snapping to existing features in your ArcGIS Online map) Export the feature from ArcGIS Online to ArcGIS Desktop to see the snapping ...
If your a student, you can access the OS's ITN which will give you the best results. If not this dataset is very expensive and I'd use the OSM version.
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