Trouble in Cities

[Murph1083]

I recently took my new TomTom to Chicago yesterday. The GPS was ok on the highway to the city but once in the city, the GPS stuggles to navigate me. Is this pretty normal with the TomTom and other GPS' in cities?

 

[lateknightucd]

I recently took my new TomTom to Chicago yesterday. The GPS was ok on the highway to the city but once in the city, the GPS stuggles to navigate me. Is this pretty normal with the TomTom and other GPS' in cities?

I had a similar experience in downtown San Francisco this week. TomTom generally worked well except down in the financial district, when it appeared to have no idea what road I was on. I found that the problem with fairly intermittent, so I just made a note of what my next turn was (based on the directions given) and watched out for it myself. I also turned the sound off. I found that there were only 5-6 blocks where I really had issues. Once I took my next turn, tracking came back and I was good to go. The unit worked fine in China Town, North Beach and Union Square. I only had issue when surrounded on all sides by buildings 40 stories and taller.

 

[Rick F.]

<snip> I only had issue when surrounded on all sides by buildings 40 stories and taller.

I've heard that this sometimes occurs when navigating around tall buildings. It has to do with the satellite signal being bounced around between building... or signal 'ducting'. I think all brands of GPS units suffer the same thing.

 

[Smokiewolf]

There's not a whole lot you can do when you have concrete and steel in the way of your line of sight to the satellites. It sounds like you handled it well.

 

[JVRaschi]

I've also had this problem in downtown Pittsburgh. It still gets me around, but sometimes the TT is "confused"

 

[96ss]

Hmmm, I had the same problem in the wide streeted, 3-4 story buildings just East of downtown LA last night. First time that I have seen that happen on my unit.

 

[Smokiewolf]

Hmmm, I had the same problem in the wide streeted, 3-4 story buildings just East of downtown LA last night. First time that I have seen that happen on my unit.

Are your GPS fix files up to date?

 

[96ss]

I haven't updated since 7.48 has been out. But my 700 has no problems in this same area.

 

[Pedro2NR]

The external antenna helps in cities. This is a known problem.

 

[equlizer]

IVe had the same problem with lower end tomtom's but its been great with my 720 and now 920.

GPS history: Garmin c330, tomtom 1 (original), tomtom XL, tomtom 510, tomtom go720 and now 920.

if your wondering how ive gone though soo many, im able to upgrade through a "friend" with a small upgrade fee each time

 

[boren]

GPS needs pretty much clear view of the skies. It doesn't work by magic, it works by receiving line of sight signals from satellites. It's amazing what new receivers can do. My older GPS units from 5-7 years ago have to be placed on the window with a clear view of the sky. Newer ones really seem to deal with reflections very well.

Driving in the middle of downtown high rises is like going down a canyon. The sky is very limited and will test any gps receiver. You turn a corner and almost all the satellites you had lock on go away and a whole new set pop up. This is really hard work. There are things you can do to help:

1. Mount the GPS on the windsheild area, don't have it tucked down in the car. This will give it a better view of the sky.

2. Try a few different area around the windshield. Some cars have a metal screen embedded in the glass that can block signals.

3. External antenna. The antenna is only $25 and you can then place the gps anywhere you want.