Safety of Walking|Biking|...

[quintona]

It is important to be able to route walking cycling users via the "safest" route. There are many factors that make up a safe route, some of which can be directly sourced from OSM, and others which would require external data sources.

As per the discussions in the mailing list: "This is something very important for FOOT/BIKE and it is similar to the already existing fastest/shortest WeightCalculation. It also requires modifications to the encoders as the flag-integer will hold some more 'safety' bits indicating not safe/somewhat safe and safe or something like this. E.g. a pedestrian is allowed to walk on a highway=road but this wouldn't be safe, instead highway=pedestrian or a track would be safe. But e.g. if bike access or even car is allowed at the same time, then the safety for pedestrian would be only 'somewhat safe' or something like this. At the same time this cost can be multiplied with the speed (or surface) or with a 'beautyness' of a way (if in parks, lots of POIs or far away from cars etc)."

The final point is where external data sources are potentially useful. The OSM dataset will never become extremely rich in terms details of features on the map. OSM will hold some tag information, but it won't hold things like rich business details. So there needs to be a base safety concept which is based purely on OSM data:

• Highway type
• Traffic direction
• Bike access
• Max speed for cars

Beyond that, things like parks would increase weights based on "beautyness", but there will be other data sources that will provide other useful data. E.g. crime reports that supported with Geospacial data, so in some cases you want to weight an arch up or down based on other factors.

I therefore the variable weighting concept needs to be quite general, with pluggable weighting factor and associated provider. This would largely be a graph generation and data model concern.

[karussell]

This will be fixed via introducing some kind of priority mechanism for bikes in #190