GeoBobC Posted February 12, 2007 Share Posted February 12, 2007 I have a Garmin 60cX with the latest unit and chipset firmware. My friend has a 60csX with the latest unit and chipset firmware. I have MetroGuide V8, non NT. My friend has MetroGuide V8, NT version. We were on a driving trip this weekend and noticed that our "Time to Destination" and ETAs (Estimated Time of Arrival) to the same destinations were different. On one 100 mile segment, the difference was approximately 5 minutes. As we got closer, of course the times got closer and finally became essentially the same. The "distance to destination" was identical on each. My understanding is that the units compute the remaining time by determining the distances on each type of road surface (freeway, highway, county road, etc.) and multiplying those distances by the speed limits for each of those types of road surfaces. The times are then added together to get a total "time to destination". What could be the reason our times are different? Anyone have an idea? Could the road speed data in the NT and non-NT versions be different? Quote Link to comment
moonpup Posted February 12, 2007 Share Posted February 12, 2007 It's probably as simple as how fast you were driving. Odd's are you are not driving at the exact same speed as the other person the whole time. You accelerate, decelerate etc..with all kinds of variables. I wouldn't worry about it. Maybe next time you can hitch the two vehicles together and let the other person pull you along and see what happens Quote Link to comment
GeoBobC Posted February 12, 2007 Author Share Posted February 12, 2007 We were in the same car, side by side. Quote Link to comment
ImpalaBob Posted February 12, 2007 Share Posted February 12, 2007 It could be that you both do not have the same settings for routing .... or like Koikeeper and myself (with identical 60C units) they each have a mind of their own and more often than not they are different. This past weekend they differed by as much as 130 feet at times .... but as we got closer to the cache the differences became smaller. Each unit got a little different "bounce" off the surrounding terrain. When we autoroute to a cache they sometimes pick different routes even with the same settings for routing. ImpalaBob Quote Link to comment
+Red90 Posted February 12, 2007 Share Posted February 12, 2007 It has been shown on other units like the iQues that the "driving speed" used for each road type is NOT fixed. It adjusts within a certain range based on historical data. In other words, it learns based on how fast you drive. I don't know if these units do that but certainly it has been proved in specific testing of the PDA/GPS units made by Garmin. Quote Link to comment
GeoBobC Posted February 12, 2007 Author Share Posted February 12, 2007 Red90, your theory is the best. We both had identical routing preferences. It has to be that the speeds used in computing the times are different. The only question is where those differences are coming from: Mapsource or the unit. Too bad these can't be configured on the unit, but "oh well". Quote Link to comment
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