2460 anomaly

My 2507 does that. It seems to have a light sensor. It also changes to night before actual sundown sometimes when it's heavily overcast and daylight has dimmed considerably. Other times it changes right on time at sunset.

One way to see if it is driven by a light sensor is to turn it on in a dark room DURING the day.

Mine never has done this before, not that I noticed before anyway. I went through another tunnel similar in length and a bit more in darkness several times today on I-676 and it didn't happen in that area, I was looking for it too.

While my 3790 doesn't have a sensor, I always leave it on night mode with the Italia theme. It's easier on the eyes.

The map data knows it's a tunnel, it just doesn't indicate so on the projected map (there is no visual cue that a tunnel is on the road, just like with bridges). The Garmin will switch to night mode while going through the tunnel. This was included in a firmware update a couple of years ago (at least with the 37xx series).

Interesting. Here's a link describing the feature on the nuvi 40/50 series:

http://www8.garmin.com/support/download_details.jsp?id=5297

Added with the March 4, 2014 update:

◦Enhanced the display to switch to night color mode when in tunnels if auto color mode is selected.

It's odd, though. The current 3.60 and earlier updates to the nuvi 24xx series do not mention this even though it must be part of one update given the video offered in the original post here:

http://www8.garmin.com/support/download_details.jsp?id=5147

soberbyker, is your 2460's software version 3.60?

Maybe the case, but like I said after noticing it happen a couple days ago I looked for it to happen again in another tunnel within a few miles of the one I mentioned and the night/day did not change.

As for the firmware being updated to do this a couple years ago I travel the same roads in my work truck weekly and a couple days ago was the first time I noticed it and only in one of the many tunnels in Philly.

My 3790 switches to night mode when I go through the tunnel at I10 in downtown Phoenix. It has been doing so since I got it 2 years ago. My other GPS (1250) still doesn't do it. My guess it must be a combination of map data & GPS features to make it happen.

Yes

A) How long was the tunnel? Even on mine, if the tunnel is too short, sometimes the GPS won't register it quickly enough and nothing happens.
B) Is the tunnel marked as a tunnel on the map data? The only way I know for sure to check this is to go to Here.com and see if it's marked (it would be dotted lines instead of solid lines).

As for why it started to do it just now, I have on idea o_O

The tunnel the auto day/night doesn't work in (I-676) is not on your here.com map as a tunnel, however it is longer than the one that is marked at here.com on I-95 where my auto day/night flipped.

If this link works it shows the tunnel I'm talking about it not working in,

http://here.com/39.9593196,-75.1734023,22,110.41,102.32,pano...

In any event this has been an interesting learning experience, although I'm not sure this type of thing is really needed.

I couldn't get the coordinates to come up for HERE.com and the link didn't work for some reason (I think that may be HERE's fault).
Anyway, if the map data doesn't know a road is a tunnel, it won't change to night mode.

This thread came just at the right time. I was driving through a downtown Phoenix "tunnel" today with my nuvi 2460 (firmware 3.60 and 2014.40 map update) and I did get night-mode to kick in when I entered the tunnel. I therefore can confirm your original finding that nuvi 2460s have the ability to go into night mode in tunnels and will do so at least for some tunnels.

Thanks Narvick, good to know. You learn something new everyday here.

my Garmin switches at sunrise/sunset but haven't been in a tunnel and observed it switch - nice to know.

Interesting!

Out of the tunnels.

Never noticed, but a neat feature. Guess I will go find a tunnel.

Must have updated the tunnel thing with the 2014.40 map update. I did that recently but hadn't been through that tunnel since until last week.

I always have my GPS's set to auto switch at sun up and down and apparently unless you have that set to auto you wouldn't see the switch in a tunnel.