Thread: iGuidance issues

Sorry dude,

Running parallel to the freeway - that's partially GPS and partially iG. Remember that "accuracy" spec for your GPS receiver? It's coming into play now. iG is being told that you're over there, so it routes you from over there. The data in iG may also be incorrect and thus plots you incorrectly.

As far as accuracy, the map data comes from NavTech, so take it up with them. Normally, a city block is located by GPS coordinates on the corners, and each street is given a range of numbers spaced along the street, so like Main St on this block is from 1000 to 2000. It doesn't tell you driveways or entrances, just approximate location.

Hope this helps,
-psyrex

Originally Posted by d_sellers1

"DING. When possible make a U-turn. DING."

Yes, a lot of users in the past have brought up the issue of excessive U-turn suggestions by iGuidance after drivers deviate from the plotted route. I personally feel I do want U-turns if they are reasonable, and I really don't mind even a hundred of them in a row if they are really making any sense. But it has been documented that many (perhaps most) U-turn prompts we get when we don't follow the calculated route is because iGuidance automatically recalculates only a portion of the route and in so doing it is just attempting to bring us back to the originally plotted route instead of generating a new optimal route by calculating a completely new route from where we are all the way to our destination.

This automatic re-calculating of just a small potion (as opposed to the full) route is there to increase the speed of auto-recalc. The speed is of the essence if you are using iGuidance on a PDA, but a PC user should really not notice any slowdown when FULL recalc is implemented.

There is a very easy registry tweak to force iGuidance to do a FULL recalc. Check the following link. Read the post in the middle of the page. (The post with the naked lady picture.)

Link:

Originally Posted by d_sellers1

Stupid program. Be quiet.

The above tweak only works for the newest iGuidance 2.1.1. In older versions, when I wanted to drive "my way" instead of the "iGuidance way" I would just use the Mute function.

Originally Posted by Marvin Hlavac

Yes, a lot of users in the past have brought up the issue of excessive U-turn suggestions by iGuidance after drivers deviate from the plotted route. I personally feel I do want U-turns if they are reasonable, and I really don't mind even a hundred of them in a row if they are really making any sense. But it has been documented that many (perhaps most) U-turn prompts we get when we don't follow the calculated route is because iGuidance automatically recalculates only a portion of the route and in so doing it is just attempting to bring us back to the originally plotted route instead of generating a new optimal route by calculating a completely new route from where we are all the way to our destination.

This automatic re-calculating of just a small potion (as opposed to the full) route is there to increase the speed of auto-recalc. The speed is of the essence if you are using iGuidance on a PDA, but a PC user should really not notice any slowdown when FULL recalc is implemented.

There is a very easy registry tweak to force iGuidance to do a FULL recalc. Check the following link. Read the post in the middle of the page. (The post with the naked lady picture.)

Link: http://www.gpspassion.com/forumsen/t...66&whichpage=4

The above tweak only works for the newest iGuidance 2.1.1. In older versions, when I wanted to drive "my way" instead of the "iGuidance way" I would just use the Mute function.

Marvin, great insight.

I would just like to add that IG, and all mapping and navi programs are not perfect. First of all, as stated before, GPS is not 100 percent accurate. It has a range of accuracy, I would say +-5 meters, which is like 13 feet. It is not something that can be avoided. It was much worse back in the day when I started with Navigation software, when the government still had SA Turned on.

Next, running a route on a Navi program is not always gonna be the "best". I recently read an article of someone testing a navigation program in NYC. He used the routing function to plan a trip from his office to his house. He complained that the program did not know that one of the streets near his office had timed streetlights, and was therefore much fater then the street that the program had chosen for him to take. And that is the difference. Routing is done by parameters, generally the shortest distance. At this point, Navigation can not tell you which streets have more cogestion then others (Even though you and I know that some streets do have more congestion then others) and it can't know "shortcuts", and it doesn;t have any idea that between 6 and 10 at night, 3rd avenue has times streetlight goin uptown while the FDR drive is a parking lot, but that during the middle of the day, 3rd avenue is bumper to bumper while te Drive is free and clear, and things like that. Navigation is for getting places that you have no idea how to get to. If you knew how to get there, then you don't need the routing of a Navi Program. Navi will get you there, even if it is not what might be the "Best" way to do it. Sometimes when I am in a place that I am not familiar with, and I want to get home, I will just hit the home button, and once I am on a freeway that I recognize, turn of the Navi, cause I know how to get home from there. NAVI is great for the places you are unfamiliar with.

Marvin, I wonder since I know you have done the complete recalc registry tweak, if you have noticed that the U-Turn prompts have been reduced or eliminated. If you have, let us know. If not, I may be doing some testing soon to check it out.

Michael

* * * Click to enlarge * * *

The above is a sample of what you can experience before and after the registry tweak ;-)

Yes, once you try it you will wonder how you were able to live without it ;-)

...and one more pic:


* * * Click to enlarge * * *

Sorry to hear that. I'd recommend one little add-on I developed that manually forces FULL recalc (a click of a keyboard key), but that doesn't function without a keyboard...

Yes, 2.1.1 upgrade is the only option for now :-(