All these devices create their own plot, but I've found Google Maps and TomTom to be nearly identical in their interpretation of roads to take between waypoints. Still, with any of them you need to create enough waypoints to make sure the program knows what you want, especially when you prefer specific back roads.
That's what I don't understand. Why can't a program like Tyre / MapSource / RouteBuddy or whatever software application you want to run allow you to plan your route and then download the route, not just the waypoints to your GPS navigation device of choice? Why does the device only accept the waypoints and route between them with it's own calculations?
If the software on your computer and the GPS device could transfer routes instead of just waypoints then you could design the route with minimal waypoints. The latest incarnation of Google Maps is a great example of how it should work. With Google Maps the way it is today, you can just give it your start and end points and drag the route on to the roads you want it to take by "rubber banding" the route. Google Maps makes little white circles at your mouse cursor where you release the button but those are not "way points" they are just intermediate points to "shape" your route.
I realize that Garmin MapSource can do some of what I am talking about. There is a concept of shaping points in MapSource and it will work kinda like I described it if your follow very specific rules in MapSource and if you download to a Garmin GPS that knows how to handle these shaping points. The zumo for example. The problem is some of the Garmin devices don't work the same way and just see these shaping points as regular wapoints.
The problem with too few waypoints is the fact that the GPS device calculates it's own route between the points. Your software of choice may show you the route you intend to take between the waypoints you have plotted but with too few waypoints defined, it's possible that your GPS might choose a different route for you. The difference will probably be slight but there still could be a difference. Not really a big deal if your riding by yourself or even with a small group where your the only one following the GPS. The problem is that if your in a bigger group and you have more than one person leading different smaller groups, one GPS device even from the same company, could interpret the route differently and some of your riders are led one way and some of them are led another.
So the current solution for most riders is to just have more way points thereby forcing the GPS device to plot the route exactly the same way on all GPS devices. If your put enough way points into your route the GPS devices will only be able to make one logical choice between your points. The problem with too many way points though is that unless the device supports this idea of shaping points and you have plotted them just right in MapSource, then you end up with the device telling you that you have reached your destination or something to that effect every time you pass through a waypoint.
Many of the way points you plot on the map are not "destinations" but just points to shape your route to force the GPS to take the roads that you want. You don't need the device telling you that you have reached that point because it's not a point you care about.
It seems to me that this could all be solved if the software and the devices would just share the route in addition to the way points. It certainly doesn't seem like it would be that much data, it seems like it would just be textual in nature to do this and text doesn't take a lot of space in the world of computers. Many of these GPS devices now come with multiple gigabytes of storage so it shouldn't be an issue. I'm not a developer so I don't know what it would take to program something like this but it seems like the next logical step. I think it would make these devices a lot more useful to riders and a lot more user friendly.
I suspect the problem is that, while we as riders would love these features, most people (drivers) could care less about all the features we want. I suspect most people just want to get in their car, input a destination and have the GPS get them there in the quickest or easiest way possible. Look at how many great GPS devices there are on the market at low costs with advanced features that have absolutely no way of taking to a computer to download or upload data of any kind except for maybe firmware updates to the device.
Okay there's my GPS rant. It's over now, you all can return to your regularly scheduled programming.
