dhc8guru

I figured out that Audi's speed limit camera also needs some other information for it to work. I don't think it just reads the signs as Audi leads us to believe. The reason I say this is their is a new freeway that I travel daily that was once on old two lane road. My Q7 still thinks the speed limits are 35 or 45 mph. It even switches between those two speed limits even though there are at least four 60 mph speed limit signs posted along the section I drive, the system refuses to recognize them. My suspicions were confirmed to me that the system rely's on some other information for its speed limits was when I was entering onto a highway from a frontage road and the speed limit immediately changed from 45 to 65 on the display right when I entered the on ramp even though there were no signs posted.
I am kind of disappointed because on this new highway, if I try to use the adaptive cruise control and set 60 mph, the second it gets an erroneous speed limit update, it will slow down and I have to override it again.

RickObe

I can't say why it is missing those particular signs. It's not always going to get every one. If it can't read a sign for a while, I think it does default to the info in the nav database. Mine has been very good about reading signs, with the exception of the "End" speed limit on some signs.

Suggestion: turn off the adaptive speed limit following option for the cruise control in the MMI.

dhc8guru

It just keeps flashing the old speed limit signs at me on some sections, no signs in others and eventually tells me the sign recognition is not available. It does it all constantly everyday. Every other road I have driven it has worked flawless.

RickObe

Is the new freeway in the nav database? Maybe you need to update your nav database.

dhc8guru

The car is a couple weeks old and when I got it I checked the nav and it said it was up to date. I will check it again. Google maps shows the new freeway but with sections of it incomplete. Its been open for about 8 months.

Cadx6

Sounds like you might have a malfunction with the system if you're actually getting error messages. Mine works religiously. If I'm on a Chicago area toll road that has construction going with a normal limit of 55, If I pass one of the temporary signs showing 45 in the construction zone, the system quickly recognizes it and changes the display in the VIC to 45.
I also mentioned in another thread that when I was on a two lane road with a posted limit of 50, I passed a kind of non-standard sign that resembled a speed limit sign advising that "IL 68" was the next intersection and the system changed the display to show 65. Apparently it thought the 8 in 68 was a sloppy 5 .
It's happened twice at the same location.

Count Rushmore

Flashing means you are trying more than X over the last speed sign that it has recognized.

You can disable the overspeed warning in the MMI

dhc8guru

Flashing was a bad choice of words. Not flashing as in over speed. Just normal speed limit alert.

The malfunction only happens on that one stretch of road. Everywhere else it works flawless.

dhc8guru

So today with the cruise control on this same stretch of highway, a different section then I normally drive, the speed limit is 60 mph. All of the sudden, the cruise slows down to 40 mph (with a 40 mph traffic sign flashing and in the HUD). There were no speed limit signs what so ever along the road.
I took a long road trip on Monday and the system work great with the exception of one stretch of highway where it failed to read two 70 MPH signs.
So at this point, I am pretty sure the system relies on other information other then just reading the signs.

srbsq7

I believe it uses speed info included in the map data.