Winter mode for offline car routing

[adrien-github]

Hi,

OSMand offline car routing in mountain can be surpising in winter. For instance I would like to go from Remiremont to Mulhouse through the Vosges, France. 2 roads are available (see the 2 GPX tracks, I just removed the extension because Github won't allow it):

• the first is by the pass of Oderen, which is the best way is summer
• the second is by the pass of Bussang, which is the best in winter because the pass of Oderen is tricky without snow tyre and the road of Bussang is very straight, at lower altitude, so with less snow.

I think it could be a good feature to have a Winter mode in the offline routing, to take into account the specific condition of winter : road closed because of the snow, prefer straight roads without zigzags, take into account the altitude, etc.
It might be a good idea especially for tourists, who follow the GPS without knowing the country, and might be trapped on dangerous road in Winter without the necessary equipment.

[sonora]

We must not fool ourselves into believing that -state of today- software can make all the best decisions for us all the time, in an automated fashion.

As much as AI is improving, the old principles of causality will always remain in place:

• you must have all relevant data on which to base any decision
• you must have an algorithm you trust to find the "best" solution, where "best" may well contain any amount of personal attitude and values

As to your particular request: Yes, there may be some data in the maps aiding a decision here (altitude profiles, roads straightness, road winter closures, etc.), but I am rather convinced that in many cases you may still want to first take a look at the weather, and then at the map, and that may be the more prudent way to solve this question for still some time to come ... :)

It is the old experience that a rude instrument in the hand of a master craftsman will achieve more than the finest tool wielded by the uninspired journeyman. — Karl Pearson

[adrien-github]

Hi,
I fully agree with you about being caution on the road, especially on winter. But there is also accident due to people who follow blindly GPS, like this one (in french, sorry):
http://france3-regions.francetvinfo.fr/grand-est/vosges/accident-train-camion-docelles-88-1184269.html

On my request, I just think it would be an improvement of OSMand to be able to deals with these constraints, as I do appreciate when OSMand warn me about pedestrian passage, speed limit, etc. These data could be mapped in OpenStreetMap.

But I also understand if it's not a priority for you.

[sonora]

Main issue is: We need a positive set of criteria to evaluate what should be preferred and what must be avoided in "winter" mode. Things like winter closures of mountain passes or elevations changes, if that is in the map data, can objectively be considered, while things like "straightness of roads" are rather hard. And then we need an algorithm to combine all these frame conditions and weigh them vs. each other - that's a science by itself. Honestly, I see no quick way to get to any decent implementation any time soon...

[cxxuzbim]

Fixing #1794 would help with roads that are already properly tagged with known restrictions.