After some experimenting and help from the Belgian OSM Community, I figured out how to tweak the parameters for the routing engine and steer the navigation process. It seemed as if the technical documentation was missing, so lets write it here.

The parameter file: routing.xml

All parameters for the routing file are stored in a single XML.

You can find this XML on the OSMAnd github. Head over there, and download it. EDIT: By now, all the documentation has been included upstream. Everything you can read here, you an also find in the github routing.xml file. This diary entry can still serve as a gentle introduction.

This document should be placed in a place where OsmAnd will find it. As I chose ‘external storage’ to store my maps (settings -> general settings -> Data Storage Folder (under miscellaneous title), adding this custom routing is easy. Plug your phone in your computer and go to the path /sdcard/Android/data/net.osmand.plus/files. Copy routing.xml over.

Reading the parameter file

routing.xml is actually documented quite good! Read the docs there to get some general idea.

Adding an option to a profile

The parameters are split per profile. I edited the bicycle profile, as that is what I use most (also see my previous diary entry).

Over there, add a toggle, e.g., if you want to avoid sett surfaces:

    <parameter id="avoid_sett" name="Strongly prefer asphalt and paving stones" description="Tries to route around sett and cobblestone, ideal if riding with a cycling cart" type="boolean"/>

The id is the name you’ll use in if-statements, the name is what shows up in OSMAnd. Save the file as described above and restart OsmAnd. Start navigation to somewhere. If you click the settings (the cogwheel on the bottom when starting navigation), your new parameter should show up!

Tweaking weights

Routing considers three major aspects:

• access
• speed
• priority

Each of those aspects has its own section in the xml; you can’t miss them.

Access

Access deduces if this road can be used or not. This is very hard: yes or no. If you want to create a profile to cycling with your toddler in the cart, and that toddler wakes up from the sett stones, you can add the following to avoid a condition in all cases:

   <select value="-1" t="surface" v="sett"/> -- never ever enter a set road

Of course, you might want to avoid unknown surfaces too:

   <select value="-1" /> -- Default: no access
   <select value="1" t="surface"/> -- only if a surface is known, allow access

And if you mix in the toggle, you’ll get:

   <if param="avoid_sett">
       <select value="-1" t="surface" v="sett"/>
  </if>

Speed

The other aspects are tweaked similarly:

Speed is the maximal practical speed on a certain road. For example, if sett slows you down to 5 km/h; then you can tell the navigation:

    <select value="5" t="surface" v="sett">

This is relative to other speeds. The default routing takes a default speed of 14.5 for cycling, so this would be way slower.

Priority

Priority is the preference of a road. If two routes are equal, the route with the highest priority is taken. However, as I modified both speed and priority in a similar way, it is hard to state the differences.

A sample use case

This custom routing can be tailored for your needs. See my other diary entry as an example and for the routes taken.

My custom routing.xml avoiding sett can be found here; the radical hiking by Joost Schouppe is over here.