GPS Cartography for Morocco: OSM vs. Garmin City Navigator
In another discussion here on HUBB, I mentioned that I had purchased Garmin's 'City Navigator Morocco' cartography for my Zumo 660, and I would report back to everyone what my experience with that map product was.
I started my Morocco tour with Open Street Maps (OSM) Morocco installed, but after a few unpleasant surprises on the first day when I was routed down dirt trails and had to ford a small river with my ST1100, I downloaded Garmin's City Navigator (CN) for Morocco, and used it for the remaining 10 days of my tour.
Here's my impression of how the two cartographic products compare:
Ease of Use
The advantage of OSM is that you can easily load it onto a computer if you want to use it with BaseCamp or MapSource. CN can't be loaded onto the computer, which means it can only be used with BaseCamp (not with MapSource), and then only when the GPS unit is connected to the computer by USB cable.
Cartographic Detail
Both OSM and CN appear to have pretty much the same roads on them. It's possible that OSM might have more 'trails' (off-road information), but I didn't investigate this, because my ST1100 is pretty much a pavement-only motorcycle.
CN contains far more 'road attributes' than OSM (paved vs. unpaved, road width, speed limits, etc.). This is important if you want to be able to rely on the GPS device to create routes for you. It is less important if you intend to create your own routes (in other words, if you don't need or want auto-routing).
Other Details
CN displayed the speed limit for roads on the GPS device, but it was not always accurate and could not be relied upon. OSM did not support display of the speed limit on the GPS device.
Conclusion, Summary
Both products display pretty much the same 'picture' on the GPS device. This means that if you plan to navigate primarily by reference to paper maps, and just use the GPS device to confirm your location, there is no advantage to spending $100 on CN when you can get OSM for free.
CN does a much better job of auto-routing than OSM, most likely because CN contains more invisible 'road attributes' than OSM does. This means that auto-routing preferences you have set, such as 'avoid toll roads' or 'avoid unpaved roads' will be respected, and you can put a fair amount of trust in the route that the GPS device calculates.
But, if you plan to create your own routes by stringing a number of waypoints together and then having the GPS device 'connect the dots', so to speak, I don't think it would be worth the $100 to buy CN.
Bottom Line: If you intend to heavily rely on auto-routing, get CN. If you intend to create your own routes, or simply use the GPS to confirm your location as you navigate by reference to paper maps, OSM will do the job at no cost to you.
Hope this info is helpful to others in the future.
Michael
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