Trip times different in BaseCanp vs Zumo 590LM GPS

The difference is probably due to different times being allowed for different road types. Your device learns your driving style and adjusts average speeds appropriately. In BC you can manually adjust them.

Thanks, but...

The difference is probably due to different times being allowed for different road types. Your device learns your driving style and adjusts average speeds appropriately. In BC you can manually adjust them.

How does this explain the discrepancies within BC itself?

You can adjust the average speeds for each road type in each activity profile in Basecamp. Look at the bottom of the page in the Routing tab.

You may be able to match the average speeds used in your device, but you will have to do it by trial and error.

SUSSAMB suggests that your device will learn your average speeds but my tests on a Zumo 550 do not support this. Admittedly, this device is over ten years old and the newer devices may have this capability.

As a retired software engineer, I wonder whether the receivers have enough grunt to do the necessary calculations without affecting the response of the unit. Also the calculations will be affected by traffic conditions and weather, so the averages would keep moving. If you use the device for your daily commute in heavy traffic, then the averages will be wrong for your weekend trip in the country.

It is, after all, just an estimated time of arrival.

SUSSAMB suggests that your device will learn your average speeds but my tests on a Zumo 550 do not support this. Admittedly, this device is over ten years old and the newer devices may have this capability.

There's some info here http://www.poi-factory.com/node/45710

I did have a link to a Garmin FAQ on this but can't find it, but it's quoted in the first post of the POI Factory thread.

FenelonPaul there is another possibility here that could be causing some confusion and has nothing to do with BaseCamp. How are you verifying the length and time of the route on the Z590? If you are simply selecting the route in Trip Planner and looking at the info on the summary page, I have found this to be nearly always inaccurate, and will not agree with BC. What you need to do is drill deeper into the menu. With the route selected in Trip Planner click on the MAP button to bring up the whole route on the map. Now click on the Tribar button in the upper left corner of the screen, then tap Review Trip on the window that opens. This will bring up another page showing the distance, time and turn by turn directions. I have found that the information in this summary nearly always matches BC. (That is of course assuming all avoidances and routing profiles are the same on teh 590 as they are in BC).

As an example I am looking at a ride I am doing tomorrow: the first screen shows 279 miles and 6hr 10min. Going to the Review Trip page shows 262 miles and 5 hr 26min which matches the BC route exactly.

The other distance and time probably includes the distance and time from where you are now to the start of the trip.

That was my first thought but in the example I posted I was over 300 miles from the start point.

But where did your device think you were?

If indeed it had your location then my idea is clearly wrong!

Yes, the device had my current position. This is a very consistent occurrence.