[mkgmap-dev] Routing Algorithm of Garmin

Tue Aug 19 17:56:25 BST 2014

Cze´sć Andrzej,

thanks for this (bad) information. Looks like the Oregon 600 (an outdoor 
device) uses the newer algorithm.
Well, it means, I can now stop optimizing for the "correct" route, and 
perhaps rather try to "optimize" the calculated time for the selected 
route (i.e. get it closer to my driving times)...

Am 16.08.2014 14:46, schrieb Andrzej Popowski:
> Hi Bernhard,
>
> Garmin has 2 version of routing algorithm, older and newer. Older is 
> used by Mapsource, older nuvi, probably by outdoor devices. Newer 
> algorithm is used by BaseCamp and last 2-3 generations of nuvi.
>
> Newer algorithm is designed for speed of calculation rather than 
> quality of results. Finding fastest way is based on road classes. At 
> longer distances device uses only class 4 roads ignoring shortcuts 
> with lower class. That's why you can optimize route manually.
>
> Older algorithm is more precise, it can use lower class roads, when 
> class 4 roads are missing. Calculations are longer. But probably you 
> still can find better route manually.
>