nuvi - Odd Routing

I experienced the same thing while plotting a new route using mapsource. I found in that instance that by changing the default preferences toward more highway, it stopped doing it. Apparantly it could not find another route besides the highway, but was trying to minimize my time on the actual highway by using the off ramps and on ramps.

Is your routing set to Fastest or Shortest?

Should I have it set to "shorter distance".

It almost seems like there should be a "most sensible" setting, too.

B_P
Skip

No, my experience has been that fastest usually produces the best results. There's probably no real explanation. These off and on ramp configurations are somehow confusing the routing engine to make it seem like they are the best option.

Unfortunately, there are always likely to be situations where the routing isn't perfect.

Since most GPSr are accurate to within 15-20 feet and most highways in Southern California are 4-5 lanes wide ( plus HOV lanes too ), and each lane is about 10-12 feet in width, it's possible that being in the far-right lane, you are actually 50-60 feet "off the highway" as viewed by the GPSr.

It would be interesting to see if your unit performed the same if you rode the far-left ( i.e. fast ) lane. Of course, the term fast-lane is an oxymoron for So Cal.

Having driven those concrete jungles for decades, I can see how this could happen.

dd

Yo Skip -

The first time I observed this phenominon, I called my best friend and told him about it: He was convinced that he had to buy a nuvi6xx.

This happened to you after your traffic receiver found traffic on your route. Since traffic is only reported for freeways (not including on- and off-ramps, the fastest route was to lead you off the freeway, and then on again, leapfrogging some traffic...theoretically. This could be a good tactic, but since off-freeway traffic is unknown and controlled-intersection wait times are not specifically considered, who knows?

My favorite routing advice from the nuvi660 is when it feints a freeway exit taking me on to separated transition lanes and then back on to the main lanes without ever having left the freeway...just like someone with local-knowledge.

Enjoy!

Well... Almost. I was at least one lane away from the exit lane, and the nuvi actually told me to take the exit. Because of the tendency for the nuvi to "stick" to roads, it thought I had actually taken the exit, and gave me additional instructions to get back on.

Yes, that's exactly what it appeared to be doing, but I avoided following the nuvi's instructions because I didn't want to tempt fate. As I passed the off-ramp, and saw what I would have had to do if I had followed the instructions, I thought, "Gee, I could have skipped ahead of some of this mess."

I knew where I had to go, just not necessarily how to get there. Maybe I should have put more trust in "Sheila". I still got to where I was going, too, with time to spare, which I suspect doesn't happen very often anytime a SoCal freeway is involved.

Hi, everyone! I was about to offer my 2 cents worth on this subject. On a recent trip to Suffolk, VA (which I've made many times) I decided to allow "Jack" to guide me. On the way down, between the Chesapeake Bay Bridge-Tunnel and Suffolk, "Jack" told me to get off I-64 onto I-264. The signs to Suffolk said stay on 64, so I ignored "Jack". On the way home I wasn't paying attention to the road signs, and allowed "Jack" to veer me onto I-264. We ended up stalled in draw bridge traffic. I was convinced that "Jack" had erred, but as it turns out, it was I who erred. My Nuvi 660 is set to "fastest" routing, and after reviewing my routes on Street Atlas, it's easy to see that "Jack" was indeed trying to take me the shorter, fastest route. Had it not been for the raised bridge, he would've succeeded. I've traveled south taking the same routes for years, convinced that I was taking the best route. I've never given much thought to trying a different route, but "Jack" has caused me to "see the light".

Miki

Check to make sure your system is set to quickest rather than shortest routing. My 340 and 5xx will take you off the Interstate to go 1 mile through a small town with 3 stoplights rather than go 2 miles at 65 mph on the Interstate even if the time is several times longer that staying in the highway. Once I set the routing to quick instead of shortest it seemed to straighten it out.

Crashmanager

I experienced the exact same thing on a trip I just made from Texas to Arizona. When going through San Antonio, their was construction and my 2720 kept telling me to exit at a certain exit and continue until the next ramp and then get back on 410, all the while I WAS on 410 and never needed to take the exit. It repeated this 3 times...telling me to take a certain exit....only to tell me to take the next ramp to get back on the same freeway 410 that I was on all the time. I never had to take any of the three exits. All I can figure out is that because of the construction, the freeway was not on the original "path" and so the garmin 2720 kept trying to re-route to get me back on it. I had a similar experience when going through Tucson, Arizona...more construction and minor detours and I kept getting instruction from my 2720 to exit and take the next ramp to get back on the freeway. It seems like every major city has these construction areas and as long as the hwys and freeways are torn up or slightly "moved" to accomodate the construction, there are going to be major problem with garmin maps and directions. This sucks!!
PS, my unit is always set to the fastest route.

I was traveling over Thanksgiving, and had a quirky thing happen with my unit. I was headed South and instead of wanting me to take the South bound exit, it wanted me go straight, take the first emergency vehicles U-Turn over the median and then take the North bound exit.

Check out my weird routing experience.

http://www.poi-factory.com/node/7457

Unfortunately, I still have no reasonable explanation other than "it's not a perfect tool."

It is routing you around traffic. Unfortunately, 80 percent of the time it isn't feasible or necessary because the accident or slow traffic it thinks is ahead of you or that you are currently sitting in isn't there any longer. The traffic receivers don't update nearly well enough. Of course leap frogging off and on the highway sounds like a great idea but the unit doesn't realize that you'll typically be sitting at a red light at the top of the ramp for 5 minutes at a time. It's not a perfect science but far better than the old paper maps. I was initially a bit disappointed when I first became a GPS user but quickly realized that there is a learning curve on my part and routes have to taken with a grain of salt. I use my 680 about 12 hours a day on average at work and all in all believe me it's worth having. It has really taken one stressful aspect of my job out of my hands.
Kerry

I agree with MM. I think when the unit is set to shortest distance, it doesn't calculate the distance from point to point (origin to destination) but form sigment to segment of the roads resulting you to go off the highway and coming back to highway again and again. My prefeerence would be shortest when driving only inside the city.

While driving to Niagara Falls from Virginia, MapQuest also did the same to me, taking off I-270 to local road and bringing me back to highway again and again.
WindChill

I am beginning to loose faith in my nuvi 350 but maybe the satellites were just too busy over Thanksgiving to give the correct directions. Traveling from Dallas to Roswell NM it tried to route me north on a longer/slower route going both directions. When it finally gave up recalculating it showed my ETA in a shorter time. It was set to fastest route.