A correspondent asked me to have a look at a .gpx for a 300km route with a view to tidying it up and making it suitable for 'Follow Road' routing on a Garmin Vista Hcx with CityNavigator with the rejoinder 'be sure to tell me what you did so I can do it next time'. So with that in mind I thought I'd document my approach here so he can do it himself this time. Heh heh.
Opening the GPX using Mapsource the immediate issue was that the route consisted of 98 Viapoints of which about 90% described the first half of the route(!?!). The problem here is that (IME) under certain conditions the GPS will ignore Viapoints in FollowRoad mode, which is bad, and the return leg was vastly underpopulated with checkpoints, also bad.
Essentially there are four things to do:
1) Convert the Viapoints to Waypoints.
Viapoints are easily recogniseable because the properties are non-editable in Mapsource, they are literally just placemarkers. When you view the Viapoint properties, all the fields are greyed out. In contrast Waypoints are editable. You can give them user friendly names and select appropriate marker types (flags).
To convert Viapoints to Waypoints I use a freeware utility called WINGDB3 (google for it). It will perform a number of transformations on GDB routes and tracks, #1 in the list being convert Via points to Waypoints.
2) Review the route to make sure the waypoints are where you want 'em , and give them appropriate names
Some GPS aficionados use the name field to number the waypoints with junction descriptions but that's a bit oldskool for me. I prefer to use simple descriptive town/road names. If you go off route for some reason (visit to cafe, bikeshop, supermarket, whatever), its easier to pickup the route again by asking the GPS to goto a waypoint called 'town name' rather then '34 SOX'. More to the point, I place Waypoints in the middle of a road sections rather than at junctions as (a) if you place the waypoint on the junction, the GPS will display a warning of the impending waypoint rather than instruct you how to navigate the junction and (b) you will need far fewer Waypoints if you mark key roads you need to pass through instead of every junction.
3) Tidy up the Waypoint flags so Main and Info controls are clearly identifiable
Open the route, select all the Waypoints, click on Waypoint properties and select an appropriate default flag. I use Blue for 'route' waypoints, then do the same for the main controls (red) and Infos (green). Using a GPS its real easy to sail past Infos oblivious of their existence!
4) Divide the route into sections with a maximum of 50 Waypoints, which is the maximum allowed in FollowRoad mode.
I aim to set the interval between Waypoints such that the route between them is fairly unabiguous and find this generally allows a 200km route to be described in less than 50 waypoints, i.e., one route 'file'. For a 300km I'd break it down into two route files. To divide the route up into sections, select the route, right click and click on 'Duplicate Route'. Then open the new route and clear the 'auto rename' checkbox, rename it as appropriate and delete the Waypoints for the first half of the route, then do the same for the original route, setting it up to cover the first half. If you get it wrong you can transfer blocks of Waypoints between routes using 'cut and paste'. Just make sure you keep a backup!
As is often the way its often easier to simply start from scratch, in which case my approach would be to set Waypoints for all the main and info controls using red and green flags, then flesh out the route with blue flags using the principles described above. YPYMATYC.
Of course, there are other approaches. You might prefer to load the route into Bikely and edit the route from there, or maybe you prefer to use tracks, in which case you can use WINGDB3 to generate a 'track.gdb' from your 'route.gdb'. You can use 'cut and paste' to copy the tracks back into your route gdb so that way you have both dynamically generated route and static track information on the GPS for a 'belt and braces' approach. Note that you will need to 'filter' the tracks down to 500 trackpoints (see track properties) to prevent them being truncated on loading onto the GPS.
Hours of fun? Well it sounds like a lot of work but isn't really. Still, at least when you setoff you will be familiar with the route!
