Downtown Chicago Problems with Nuvi 350??

from experience, I know that large cities continue to add/change their roads constantly. Were you in an area where there were new roads?

You shouldn't have had issues with receiption since you have SiRFIII

Even with the SiRF chip, if the tall buildings significantly block your signal, you will experience problems.

However, recalculating typically isn't a sign of signal loss. Can you give some additional details of exactly what you are doing and what is happening?

No new streets. Every time I'm in the heart of downtown Chicago (i.e. Michigan Ave, State Street, etc) (for those that are familiar with Downtown Chicago) and I plug in a destination down there, it will give me directions, and I'll follow them, but it'll change over and over again telling me to take a different route. Sometimes that route won't take me to where I want to go.

I have full signal when I'm down there, so I don't know why it's doing this. I have no problem in other places in Chicago, just the downtown area. Are there places by major buildings (i.e. Sears Tower, Daley Center, etc) that screw up the signal for GPS's? Or is it that I have a defective GPS? Like I said before, it works perfect everywhere else I've taken it, just not there. Don't know why.

Doesn't sound like a defective unit.

Let's check a few things.

What navigation preferences do you have set?

Fastest/Shortest
Car/Pedestrian/Truck/Bus
Avoidances? - U-turns/Tolls/Highways etc

Anything else you may have set? Are you following the route that is calculated?

My settings are as follows....

Faster Time
Car/Motorcycle
Avoidances/Enabled/Traffic/Unpaved Roads/Ferries

I plug in a destination, then follow the route that is initially given. I follow it directly. Then for some reason, as I'm following it, it'll recalculate and give me another set of directions. I didn't miss a turn or anything like that. I follow the directions as is.

Sometimes when it recalculates, it'll give me directions and it won't be anywhere near where I want to go. It'll recalculate even though I'm following the directions it gave me. It's very odd.

Did the recalculation happen when you are close to a turn or when you are n a straight road? If it recalculates close to a turn, it might because the GPS does not have enough accuracy so the unit "thought" it has passed the turn and therefore recalculate. Check the accuracy by pressing the signal bar to bring out the satellite screen. You might want to compare the accuracy at the spots in downtown where recalculation happened and at regular spots.

A LOT of people report having trouble in downtown Chicago and New York; I'd venture a guess that applies to almost everybody.

Are you SURE that your destination changes?

All the reports I've seen relate to not being able to calculate your PRESENT position correctly.

In order to see what is really happening, you're going to have to LOOK at the map and examine the route. If you are just listening to the prompts, you may not be getting a true picture of what is really happening.

I think it's just the very tall buildings and narrow streets that are interfering with the signals. There may be some multipath going on, too.

I stopped at the light on State and Monroe and after being stopped for a minute, my car on the screen jumped ahead one block and it wanted to recalculate. And there was almost zero signal under the el tracks on Wabash. No suprise there, of course. The Loop is really tough for GPS signals.

I made a post about this too. I live in Chicago and REALLY needed my gps that day. Needless to say, i wasted more gas than i should've because i was lost for a while and going in circles!!

I'll check again tomorrow, due to that I'll be downtown tomorrow. But from what I've experienced so far, that's what seems to happen. I'll let you know what happens.

Yeah, same thing happened to me in Boston. MM is right, it probably isn't signal issue if it is recalculating. I know that in Boston, the streets are so close together that if you miss one turn, by the time it recalculates, you have gone past the next street and it becomes vicious circle.

Did anyone else notice that he has "traffic" set as an avoidance? I don't have traffic on my nuvi 260, but will that cause this if it keeps thinking that he's approaching a traffic problem?

I had exactly the same issue with my Nuvi 360 while traveling through downtown San Francisco. It would almost continuously recalculate until I got out from between some very tall buildings. I wouldn't worry about it, but it is very annoying!

I avoid downtown Chicago like the plague. People can't drive worth a crap there. If I really must go I will either use Train or the CTA bus. But if I must drive I will use the GPS to simulate the route before I leave. Write down the directions and follow what I wrote. Last time I went downtown was for the Thankgiving Day parade. Wanted to find a Walgreen's, so I started up the GPS and started walking. I found the Walgreen's 4 blocks from where my family was standing, but the GPS didn't even get a signal. That is when I decided it would be useless in the steel and concrete canyons of Chicago.

The traffic "services" don't report on downtown streets of major metro. areas like New York and Chicago because they are ALWAYS a problem!

The traffic avoidance only works if you have a traffic receiver attached to your GPS unit.

I have experienced the same things with both Nuvi 350 & now with my 660. It is very frustrating, because getting to places downtown is one of the major reasons I got the gps in the first place, so that I wasn't dodging pedestrians AND looking for street addresses!

I now try to take a peek at the next 3-4 turns before I get rolling, so that when it goes 'recalc-crazy', I at least now the basics of the route it initially mapped out. I definitely think that the Nuvi gets confused in the 'canyons' bewteen the tall buildings. I had hoped that some of the software upgrades would address the issues, but no luck. It is very frustrating....

I "recalculate" in downtown Fort Worth, which pales in size to CHI. I've always assumed that its losing signal too.

I have a nuvi 680. It is a recurrent issue with all those Sears Tower-like buildings all around. I brace myself for "recalculating" once I go downtown Chicago. No particular setting on the Nuvi is necessary to undergo that kind of ordeal. I use a traffic receiver - it is of no use when the receiver cannot even "see" properly. Don't blame your particular receiver: the issue spreads around fairly well for most people.

Hey pecluvpj,

I think it's the buildings. I have an Initial GM-351 and just moved here from New York 2 days ago. In Manhattan, same as Chicago(I live in the South Loop) it goes absolutely haywire. Continually recalculating and sometimes not able to pick up a signal.

However when I'm not in a city, Queens, Brooklyn, Long Island etc., it works just fine. At least in Manhattan I got a signal but it just kept recalculating. I guess I'm going to have to learn Chicago's city really fast.

Thanks for the information. Luckily enough, I know the downtown area pretty well already, but it is very annoying. I think it has to do with just the area, cause I'll be away from tall buildings (i.e sears tower) and still in the chicago downtown area, and it will still go haywire. For instance, by State and Wacker. For someone that works downtown often, and has to drive, it gets annoying that I can't use my gps there. Is there anything Garmin is doing to fix this?

I don't want to be rude but......have you not been understanding what everyone has been saying ??
All brands of GPS have similar problems in locations like downtown Chicago.

I can't drive my car on Lake Michigan. Is GM doing anything to fix this??

I understood what everyone was saying. I was just curious to see if anything was being done about it. Like you stated, it is a problem with all brands of GPS. Figured one or more of the brands would be working on a solution to it.

For all I know, there could be a "fix" already available. This GPS "thing" started with the military; they may have "units" that are still able to function in places with lots of reflected images, lots of noise, low signal strength, etc.

If you have about $10K to spend, maybe you could get one!

Bottom line is: 40 years as an electronic technician and engineer tells me that there is NO practical (read that cost effective) solution.

they have the same problem wiht two way radio's the emergency personel use. The signal will be lost in big city's canyons, and any place that may be down in a revene.