Map errors?

You could possibly have your Navigation (avoidances) Set to avoid any Traffic Congestion which will automatically take you off the Freeway and by-pass the traffic problem area. My nuvi 2555 has the capability to Avoid when I press the Traffic Icon. Your device SHOULD only take you off the Freeway and bring you back, after taking you around the Problem WHILE YOU ARE ON A ROUTE.

That route through Morgantown is "shorter" therefore it is "faster."

The Nuvi doesn't know there are such things as stop lights or signs and assumes you will travel at the posted speed the entire length. That's why you should always check what the unit suggests.

Drivers should know the roads and review the ENTIRE ROUTE before they start the drive. Letting any GPS device dictate your route without reviewing it is a NO, NO.

That is exactly what I have figured out.

My advice is to get a rand mcnally road atlas to keep with you also. It will be your backup and it gives you a look at the big picture. If you are old like me I get the large print edition.

Settings of shorter distance between points versus faster route can make a difference. Once I was annoyed on a route of 350 miles, at which the GPS kept "recalculating" on every single exit for the next 200 miles.

On my way back I followed the GPS recommendation.

When I got back home I found that the GPS sent me thru every single small town with tons of traffic lights.

Lesson to learn: Map your route before going to a new place and follow your "instincts". Use the GPS when getting or feeling lost.

What you describe will happen to me on my 765T if is have the Avoidance "highway" checked.

As you probably know, you can tap the green bar at the top of the GPS to have it do turn by turn directions.

Welcome to the site.

There is a Getting Started button in the upper right of this page right under POI Files. It is worthwhile visiting this page.

To make navigation easy, most browsers provide the following option. When you want to follow a link - but still keep your current page open - you can hold down the "Ctrl" key as you left-click on a link. That action will open a new "Tab" in your browser up on the "Tab" bar. When you then left-click on that new "Tab", you will follow the link - leaving the "Tab" you are now reading open and available to click on and return here.

So, using the "Getting Started" link, you might try the "Ctrl" - left-click sequence and then return here. You can return by either "X-ing" out of the "Getting Started" page (using the "X" on the "Tab" itself) or just left-clicking on the "Tab" for the page you are on right now.

Since you are new here, I encourage you to go through a couple of the Beginner Education FAQs.

The first link makes sure the settings on your computer are such that you can do more advanced POI loading.
http://www.poi-factory.com/node/30393

The next link helps you make a backup of your GPS by attaching it to your computer. (NEVER do anything to your GPS until you have a backup)
http://www.poi-factory.com/node/30394

Let us know how we can help you enjoy your GPS.

That's not quite right for the nuvi 855. Certainly mine assumes I will drive faster than the posited limit on all expressways. Haven't yet figured out the algorithm for speeds on urban roads. It's certainly less than the posted limit.

It's (little) known that the nuvi learns your driving habits *over time* and will adjust itself according to those learned habits. If you tend to drive over the speed limit on a regular basis, your route times will be lower while the simulation speed (when simulating a route with the GPS set to off) will be higher.

However, after a hard/master reset, the nuvi will clear those learned values and use the default speed limits when calculating/simulating routes after which it will again begin to learn your driving habits.

Good Advice but wouldn't it be better to just Learn how to properly utilize your GPS Device effectively? It should be used for its intended purpose and IF you need a Map as a back up, you don't need a GPS, in my way of thinking..

I always carry a map or atlas as a backup when I am traveling in unfamiliar territory. A GPS is a piece of technology and that technology can fail. A map cannot, short of spontaneously bursting into flames.

The maps are never perfect, one version of maps I had showed a rest area where there wasn't even an exit ramp. That has been corrected. Another version of maps had a more serious error. We were on I-90 by Schenectady, NY and was using a route that I had loaded into the GPS to get me on I-88 heading for home. All of a sudden the GPS overrode my route and wanted me to take an exit into downtown Schenectady. I just kept going and after we got on I-88 everything straightened out.

Let me start out by saying I appreciate all the posts and help. This is always the best place to come to for GPS advice.

In my post I was simply pointing out the quirk in the system.
I was familiar with my planned route and had even looked at it on Google Maps before I left. Also I have my unit set for the fastest route with the only avoidance's set for u-turns (because they are mostly illegal where I live), traffic, ferries and unpaved roads. When it told me to exit I even zoomed out a little to see if the route showed going past the exit which it did not. The only reason I went ahead and exited was because I thought it may have been avoiding traffic or construction, which is something I would have had no way of knowing about since I am rarely in that area. It was only after I reached the bottom of the ramp that it changed the route to put me back on the freeway (recalculated). I have seen reports of this happening to others at various points around the country. Most people seem to attribute it to a tiny gap in the maps which the GPS routes you around because it thinks the road doesn't exist for that minuscule section. I was curious however if someone familiar with that area has had similar routing problems. I also realize it could have been due to the exact route I had put into the unit including my particular start and end points which a local person may not encounter.

On a side note, in looking closely at the Google maps satellite view of that interchange at map coordinates 39.628508,-79.989348 I see that their close up satellite images show a little jog in the picture at a point between the ramp it had me exit on and the ramp where it put me back on the freeway. I wonder if the maps Garmin use may have used the same satellite image in their creation and if that could have been involved in the re-routing because it thought there may have been a gap in the road.

Through many times being told to exit where I knew it was wrong I have learned to zoom in as close as possible and then placing my flag past the interchange as far right as I can so the Garmin knows I am going through it. When I am going to change roads I place the flag on the road after the turn and as far to the right of the lane so it knows I am going in that direction.
If it was in England or other such countries I would place the flag on the left.
After loading it to Garmin I do touch the upper green band and check the route for accuracy.

Interesting, thanks!

JGermann, thanks for the links. It was pretty detailed and I learned a lot from them.

Always nice to know that people are learning.