blown 87

I think they did do a good job over all, but average estimated speeds that work in Wyoming would not work in Southern Cali or DC or Atlanta for that matter.

For the Southeast the estimated speeds are to high unless you are a Kamakazi driver.
I know there are not any of these types here.

69gaugeman

I believe that embedded data includes speeds of the roads traveled. Otherwise you would never be even close. It would be easy for the unit to calculate your speed vs speed limit and 'figure out' how you are driving or your driving style.

jon928se

The current (ish) Garmins (I use a Nuvi 760i probably an Aus only edition) assumes you will travel precise;y at the speed limit for the routed roads to calculate the ETA. My only complaint with the unit - It puts up a target that can take you into go to jail and throw away the key territory .

Given that marine GPS ten years ago could predict your eta based on yuor current SOG you'ld think that they'ld have figured out an algorithm that would extrapolate how much in excess of the current speed limit you were travelling and recalculate based upon that ????

blown 87

Exactly!

To have a moving average of 68.9 on a 500 mile trip that includes a couple of cites and then JUST barely beat the first ETA, you are going to spend a lot of time at a speed way past the speed limit.

I have the 760 American unit.

hacker-pschorr

Isn't that the idea?

blown 87

Seven hours of it was fun and scary (fear of arrest) at the same time.

69gaugeman

Mine does. It recalculates as I am driving (Nuvi255w)

blown 87

Of course they recalculate, what we are talking about is the first ETA, not 1/2 mile from the destination.

69gaugeman

Mine always calculates down. Meaning if I drove the speed limit I would get there exactly on time.

Once I start driving after about five minutes I always end up at the destination exactly as calculated. Meaning it must have taken into account my propensity to exceed the limit.

jon928se

No. When it recalculates it only accounts for where you are now and how long it will take from there to the destination at the speed limit.

69gaugeman

Hmm. I would disagree. Unless you know something about the programming that I don't

I drive weekly from Guelph to Windsor. Once I get on the 401 (major highway with 100km speed limit) it will change the eta as I am driving. After about 5 minutes the ETA that it shows is within a couple of minutes of the time I actually get there. I set the cruise control to 117km/h.

From that it MUST take into account the speed I am doing and not the speed limit as other wise the 3 hour trip would be off in the neighborhood of 25 - 30 minutes. It never is.

Adrian_

I've used the european versions of both the the Garmin 255 and 750, and there's no chance you can make the initial time of arrival, unless your trip is mostly on highway.
Within big cities the time of arrival is so way off that it's basically a useless feature.


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1979 Euro

blown 87

I have done exactly that, like my post said, right at 500 miles and went through Memphis TN and Birmingham AL.
I may have exceeded the posted limit once.

hacker-pschorr

Road trip to Milwaukee last Thursday I shaved 11 minutes off the initial time estimate in the rain

Adrian_

Blown, I think you should specify how many of those 500 miles were on hightway/interstate. I clearly said that if you go mostly highway aso you can make it.

I found it unreliable when travelling extensive distances on smaller roads. (not to mention big towns)



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1979 Euro