Montana 750i doesn't recalculate while pedestrian walking to a waypoint

What exactly do you mean when you say "fails to calculate a revised route"? Does the Montana give an error message? Or does it not recalculate at all?

How are the settings under Setup > Routing configured? And what map are you using?

It doesn't update the route map to reflect where I am actually walking as opposed to where it thinks I should be walking, and continues to say that I'm supposed to turn left in 500 feet when I should actually turn right in about that distance where I am actually walking. As I said, I assume the Montana is using City Navigator, as I am pedestrian walking and it is routing me along city streets.

Settings:

Direct Routing--No

Activity--Prompted

Course Navigation Method--Roads & Trails

Course Alerts--On

Popularity Routing--Off

Lock on Road--No

Calculation Method--Prompted

The Montana will use the active map or map layer for calculating routes. So if you have the CityNavigator maps installed and the CityNavigator layer is active, that map is used for route calculation. CityNavigator is more geared towards motorised activities (car, motorcycle, quad, etc). For hiking/walking activities the TopoActive maps may give you better results.

You could try setting the Lock on Road to Yes, this will "snap" your position to the nearest road on the map even if your actual position is not fully on that road.

Ok so your issue may be due to that have set the activity to Prompted. If Activity is set to Prompted the settings Avoidance Setup and Off Route Calculation are not available in the Routing configuration. So try what happens when you set Activity to a specific activity, like Hiking.

Also check the maps you're using. City Navigator does not have all the trails and paths because it is a map suited for motorised activities. Try switching to the Topo Active map and see if that gives better results.

I ran another side-by-side comparison of the Montana 750i and Google Maps on my cell phone this evening. As before, both came up with the same suboptimal routing. When I deviated from the plotted route, Google Maps very quickly recalculated the route and repainted it on-screen. The Montana never did. I had to manually change the destination (to the same destination) before it would calculate a new, more direct route using paved and unpaved trails and redraw it on the screen. The activity setting was hiking, the advanced routing setting was automatically recalculate, and topo active was the active map.

Any other suggestions? I hate to think that the free Google Maps app on my cell phone can outperform my $800 Garmin Montana in an urban setting. (Obviously, it would do better where there were no cell phone towers.)

I've also started encountering the problem where the Montana spontaneously shuts off and has to be manually restarted (with the current route still active). I've read on-line that this may be due to the Montana's woefully inadequate internal resources, if you have too many maps active. I recently installed Open Street Maps, which could be causing the system to overload. My next experiment will be to see whether the shut down occurs more when I am using Topo Active alone, Open Street Map alone, or both together. Depending on what I find out, I'll start a new thread if necessary.