Nav System Advanced Discussion

[esjones]

I'd like to start a thread to talk about the deeper functions of the navigation system option on the Vibe to exchange information and ideas about how to get the most of this fairly expensive option.....1) Avg. Speed - When planning a route for you, the system uses an average travel speed on interstates as 60 MPH, and on all other roads (I think) at 35 MPH. This means that the system will nearly always show you a route that uses the most interstate miles as the "quick" route to your destination. Of course, this isn't always true, especially if you average more than 35 MPH on non-interstate roads. Both of these averages can be changed by the user, and I suspect that the 60 MPH interstate average is good, but that 35 MPH for other driving is too low. But the question is, too low by how much? Has anyone changed their average speed settings for any length of time, and if so, has it made much of a difference in the accuracy of the computed driving time, or made the unit more likely to offer you routes that aren't almost exclusively interstate highways?2) How do you use the "Guide" feature when you have POI (points of interest) displayed on the map? Looks like you can press Guide and it will show you information about the POI that is highlighted, but I don't see how to move the highlight to select other POI.3) Does anyone know how to use the "Detour" feature?

[Jahntassa]

1) I changed my speeds. Yes, and it sorta does. It'll still use your current speed to calculate time, but it uses the 'average' stuff to deal with roads that you aren't on yet.I changed mine to 40/50/65. It does make a little bit of difference. Basically tell it what you usually drive on 35 mph roads, 50 mph roads, and highway.2) Good question...i've no idea. Never bothered using it...3) If you're driving, and you want to change (detour) the route for a certain amount of time, it'll create a little side route.. I'm not near it, so i'll have to try it later to figure it out..

[esjones]

Quote, originally posted by Jahntassa »1) I changed my speeds. Yes, and it sorta does. It'll still use your current speed to calculate time, but it uses the 'average' stuff to deal with roads that you aren't on yet.I don't think your current speed enters into the calculation. If I'm stopped in traffic or just crawling along, the estimated trip time should steadily increase if it was using my current speed. It doesn't, so I don't think the system uses current speed. I think that the speeds you enter into the three types of roads is all it has to go on. Do you have documentation or evidence to the contrary?

[Jahntassa]

Not really, but some of the navigation systems i've used will not include stop time in the ETA calculation. It may just be average speeds, but I can't fully say either way. You're right, that it would increase the time, but I think it might take the current speed into account when moving, and not when stopped. I have nothing that says that, though.