Proximity alerts with TourGuide POIs versus "regular" POIs

Not really. Only if you want to be alerted by sound. They still work visually as a stand alone.

Depending on your peripheral vision, sound is good, though!

Thanks for the legwork, rmartinx, and for posting it for the rest of us.

And when you wrote:

REGULAR POIs are limited in functionality. They can be located anywhere, but if you want a proximity alert the POI MUST BE on the road you are traveling...

note that even if the POI is along the route and has a driveway from the road to the POI itself, if the POI is set back far enough from the route, it won't alert. This is why TourGuide mode is essential if you use the "schools" POI and want alerts so you'll slow down for upcoming school zones -- and why we all owe such a big thank you to MrKenFL who maintains the "Rest Area Combined" POI file. He has set each rest area's location to be the Exit Ramp for the Rest Area, not to the Rest Area itself. So when routing happily down the highway, the exit ramp will be along your route--and you will get an alert without the need to make the file a TourGuide.

I was unable to get a proximity alert to trigger on a TourGuide POI without a link to an mp3, so I presumed they were mandatory. I had hoped that it would just use a default sound (or even no sound at all), but I got no icon or visual alert until I linked an mp2 sound file. I'll keep experimenting.

Sorry, RMARTINX, but I believe you're wrong.
I have a POI file of all of the Rest Areas in Ohio, the closest of which is on I-90 just west of SR 44 in Lake County. When I load the POIs using the POI Loader, I set the proximity alert at three miles (15840 feet).
As I approach I-90 from southbound SR44, the proximity alert triggers because I'm within the three mile radius of the rest area. There is no question about it: the rest area is on I-90 and the proximity alert triggers on SR 44. It acts the same on my new Nuvi 1450 and it did on my old Streetpilot C530.

Hmm, I wonder if there's something special about the Ohio rest area file that makes it work as a TourGuide. I use the Rest Areas Combined file (from POI Factory). Using it with a 15000-foot alert distance, I only get alerts for rest areas I'll be passing (or the occasional rest area for the oncoming traffic headed the other way from me on a divided highway)--I don't get a rest area alert if I'm within 15000 feet of a rest area on a different highway. I see this both on a nuvi 750 and 855.

It doesn't work that way on my Nuvi 750. I am aware of rest area POI files that have been carefully constructed so that the POI is on the freeway ramp (not centered on the rest area itself), which qualifies as "on the road", hence triggering the alert. On my unit, if the POI is truly off the road it will not alert, even if the distance overlaps the road.

With my 855 I sometimes get RLC alerts for intersections on roads a block away from the road I'm travelling on. Almost like I get an alert for any RLC POI located in a pie shaped cone in front of the vehicle.
Mark