Wrong Speeds

The FAQ:

http://www.poi-factory.com/node/45414

I have a nuvi 2460 and tried to keep up with speed limit changes and found it a terrible job. Garmin must have agreed as the feature disappeared on later models.

On my nuvi 3597, the speed limit info is always correct, even on side roads. I have recently driven in New York, Connecticut, New Jersey, Pennsylvania, Delaware, Maryland, and Virginia.

dobs108

I drive about 12,000 miles a year on secondary/tertiary roads, and I can think of just one (1) stretch of country road that is inaccurate. I think that stretch, 5 miles at most, was perhaps changed by the local municipality in just the last year.

This is something I do periodically check, and my nuvi68 generally reflects the new speed within about a car-length or two.

On the really-back back-roads the nuvi shows no speed limit at all, but where it does it is almost always accurate.

above. My Drivesmart LMT61 is always spot on, always changes within several feet of the Speed Limit sign.

Even with the latest maps I find many speed limits shown on my 3597 different from the actual posted signs. There are lots of reasons from states/counties/cities and towns not reporting them to a centralized database accessed by Here or they recently changed due to road changes. The nos common error in my neck of the woods appears to the governing authority agreeing to citizen complaints about "speeding cars and trucks" (that belong to their neighbors).

Not in my neighborhood. Speed limit changed to 25 along sections of US1 in College Park MD a couple of years ago. Still shows 30 on my 3597 in some places where it's now 25.
Mark

Please understand that Garmin does NOT make the maps. Currently the maps are supplied (thru Garmin) by "HERE Technologies".

Telling Garmin that there is a map error is just adding another step in the process and creates another crack for the correction to fall thru.

Go directly to the map provider at:

https://here.navigation.com/north-america/here-map-creator

and enter the correction.

BTW, the only speed limit errors I've seen recently are, the ever changing "construction zones". There is one on I-64 between the 240 mm and the 248 mm that is currently 55 mph and my 3597 shows it as 70 mph. Been under construction for over 2 years now.

Funny thing is that the "Traffic Info" sign saying 22 miles in 22 minutes is not including the 55 mph zone in the calculation.

Certainly an area for improvement with Garmin - user input would certainly help, but they don't seem to be in receive mode.

There's a major tollroad nearby that raised its speed limit years ago. My Garmin still shows the lower speed limit but so does Apple Maps.

Cyclops still has red light cameras in NJ, when they were turned off in 2014.

I know they could care less, but I'm just using the 4 years as a way of illustrating to what extent they could care less.

Thinking about this, Garmin enjoys a certain status in their field. Like Apple, BMW, Oakley, etc. The brand name alone has an intrinsic value. But think about how difficult their business is, when everyone already has a free gps (their smartphone).

I've watched Nuvi displayed speed limits ever since I got a 3790 a few years ago.

I don't know the full path from actual speed limits on the ground to my screen, but strongly suspect that the first step up the ladder involves local authorities in some sense, not a huge supply of "shoe-leather" detection by employees of one or more company in the chain.

As one might expect if that were true, the accuracy I've observed has varied strongly from location to location. The worst I remember was for secondary roads in Northeast Ohio, which were bad enough that I doubted my normal practice there.

My current normal practice is always to attempt to detect the signs myself and remember them. But if I have turned on a new road and not yet seen a sign, or have forgotten the last one I saw, I treat the Nuvi displayed limit as more likely to be right than my personal guess based on road type. My limit guesses and actual speed choices tend to be conservative anyway. Evidence for that I shall offer is that I have only been pulled over for speeding once in 55 years of driving. That was fifty years ago, and the officer was on foot and let me off with a stern lecture.

Granted I am not an auditor, so I don't constantly check, but it seems that the overwhelming majority of the time, my 2595 has the right info on the display.

CC

I agree with archae86. It varies with location. I don't remember the model, maybe it was my 2460.

You could change the speed limit manually, but when you did on a road where the speed limit changes a lot the next spot you entered a speed change the change would change it for the entire road, including the last change you made on that road.

My DS61 you can't change, AFAIK, and there are a few spots where the limit was reduced but the higher still shows on the GPS.

While a nice feature relying only on it could get you in trouble.

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there was a long stretch of road, with no speed limit signs.

It helps to mention where, I know, Scotch Plains, NJ.

I don't live in NJ.

So we were not sure what the speed limit was, but we were following this Nissan Altima for about 4 miles thinking wth is going on, 28 mph?

In the back of my mind, I always think, locals know something we don't. Sure enough we went through at least 3 speed traps. Finally we saw a posted limit, and it was 35 mph.

I have a 2689LMT and live in SoCal. I've never notice the speed limits to be off, even by a foot. What I mean by that is that if the speed limit changes on a street, my 2689 changes the speed limit display right at the new sign.

I just bought a new Dodge Ram 1500 LTD with Nav and will be checking it out for accuracy in the coming months.

Driving 4 lane divided highways through east Texas, my garmin might be correct a third of the time. Similarly, interstate highways around here lag a lot behind posted speeds.

That's been my thought as well. For most of the US, the speed limits are generally spot on, but Texas is the exception.

My old nuvi 760 pretty much always has the correct speed limits. It was extremely handy last year when we spent a lot of time driving in Canada as all the speed limits were in kph. I left the muvi in mph and it translated for me perfectly.

With either my 855 or 2797 the speed limit sign on the display changes almost as soon as I pass the change of speed sign, within 50'.
Can't say about Texas, but will see in October when I drive the whole state from Texarkana to Laredo.

The built in Piece of c r a p in my car takes forever to change even though it is supposed to be Garmin based. But then I don't spend the $ 100.00+ to update the map.

There are LOTS of places where the limit is wrong. There are lots of places where the change is off by maybe 1/4 to 1/2 mile. It isn't Garmin's fault or the units fault. Towns keep changing the limit and the database just can't keep up. MOSTLY they are right on the money but you cannot go by the numbers blindly.
As for telling Garmin about the change, since it isn't their database I would venture a guess that they do nothing with your comments. Maybe writing Navtec would be a better option.

I have not noticed any major discrepancies in West, Central or Southern Texas on my RV 760. I often know where the speed limits are going to change and have watched it change on the GPS. Definitely going to pay more attention now to see if it is as accurate as I have always thought ...... Maybe I haven’t been watching it enough!

The biggest issue in my Texas travels was Hwy 287 between Amarillo and DFW where for the vast majority of the drive the speed limit was 10 mph off.

I seem to remember that the speeds were off in Kansas on the Toll road. But that was a year and two or three map updates ago.

I also find some roads is not right.

The one between KC and Topeka was on the mark last summer.
I was not on the one going southwest.

I believe that was the one I was on. I was headed to CO Springs. I take that back. I would have stayed on I70 all the way to Limon

That is I-70, I was going to Golden, CO.