Although it initially seemed a hassle, having the two products turned out to have several silver linings. First, the differing map styles actually complement each other: I found I preferred the more schematic MapSource maps for areas where roads were dense or the driving complex. It's easier to see exactly what each road is, and how roads interconnect. But I preferred the Route 66 maps for planning cross-country driving, as those maps provided more contextual information about the landforms and surrounding countryside.

So, as I planned my trip, I used Route 66 to explore point-to-point driving options until I found routes I was happy with. I then manually adjusted and input the routes into the GPS via the MapSource software. This involves clicking to create waypoints along an intended route, and then loading the series of waypoints into the actual GPS unit: The GPS unit stitches the waypoints together to display a route.

Route 66 will automatically plot a point-to-point route, and display it as a purple line on a map. This map shows a short section of a route from the A13 autobahn in eastern Switzerland (left), crossing the Rhein river into Liechtenstein (right).

Here's the same route section, as manually input to the MapSource software. Each black square is a waypoint manually entered by clicking on the map. The software then stitches the individual waypoints together to create the route, shown in purple. The result is somewhat clearer than the Route 66 version, and also can be input directly into a GPS for convenient in-car use.

It would have been easier if the Garmin V could directly or automatically read the routes generated by the Route 66 software, but it's not that simple.

The lingua franca of the GPS hardware world is NMEA, a communications standard established by the National Marine Electronics Association in the U.S. (Years ago, maritime interests were among the first to embrace GPS technology.) Any GPS worth its salt should be able to handle NMEA input/output.

The Garmin V "speaks" NMEA, as well as other formats: It can convey its positioning data to any other device that uses the same formats. The Route 66 software, for example, will accept NMEA-format data from a GPS unit (via a PC's serial port) and display your live position on its maps. (We'll come back to this point in a moment.) But routing information can only be sent to a Garmin GPS in a proprietary Garmin format, which Route 66 doesn't support. Garmin's MapSource software does support the Garmin format: It also can read your position via a serial port connected to a GPS, and can send routing information back to the GPS using the special Garmin data format.

Thus, the only way to get Route 66-generated point-to-point routes into the Garmin GPS was to first convert the route to Garmin format via the MapSource software. And that leads to the second silver lining: Although this extra step was somewhat of a hassle, it had the advantage of letting me see each route in some detail before I drove it. This not only made me more familiar with the route, but also helped me avoid some software-generated errors.

Finding And Fixing Routing Errors
For example, I found that Route 66 sometimes fumbled when calculating routes through complex intersections. In one memorable instance, Route 66 planned a route that looked fine until I transferred it to the more schematic view of the MapSource software: Then, I saw that Route 66 had plotted the shortest possible route through a cloverleaf-type interchange--including an illegal turn across oncoming traffic! If I had relied solely on the Route 66 software, I would have encountered some moments of confusion behind the wheel when confronted with this impossible turn. But instead, I was able to see (and correct) the problem in advance when I transferred the route to MapSource.

The Route 66 software sometimes was a bit sloppy. Here, it plotted an illegal and dangerous route through a cloverleaf intersection in Interlaken, Switzerland.

Manually transferring the incorrect Route 66 route to the MapSource software let me correct routing errors. For example, here's the correct (and legal) route through the same intersection.

There were some other snags: Neither software package's maps were 100% accurate (no map ever is). For example, some turns and intersections were wrong due to construction changes that happened after the electronic-mapping software was finished. (There's a similar problem with paper maps, of course. It's hard to keep any road map totally current with road conditions.)

Ongoing construction detours also were an issue, although this varied hugely from country to country. For example, we were surprised to find that the Swiss highway department doesn't live up to the vaunted national reputation for efficiency. Although Swiss drivers were excellent, highway detours and temporary construction rerouting was often very poorly marked. In contrast, the Italian drivers often acted insane, but their roads--including detours and construction rerouting--were usually very clearly marked and easy to follow. French, Austrian, and especially the German roads also were excellent. But even when the signage was poor or detours and road changes threw us off our planned track, the GPS let us know when we went astray, and helped us navigate back to our planned route.

Some roads offered other special challenges, too: Bridges, tall buildings, long tunnels, and--in Alpine regions, concrete avalanche shields--can block the GPS signals, rendering the GPS temporarily useless. This creates a potential for confusion in cases where a required turn or route change happens immediately after exiting a tunnel or other signal obstruction: You may find yourself past the turn or route change before the GPS reacquires its bearings. What then?

Part of the answer is in familiarizing yourself with a route before you drive it--something the manual review and entry of the mapping data forced me to do. It's a good thing to do, anyway, simply to help avoid surprises.

But there's lots more you can do to help overcome the unanticipated snags that will occur in any long trip, too.