Figure 105: Main Menu 2 of 3
As mentioned earlier in the review, Map Share allows you, and other TomTom owners, to correct mapping errors directly on the GPS, and then share those corrections with other TomTom owners via TomTom's HOME software. Using Map Share, if you're driving around and notice an error on the map, you can mark the error, as well as the correction, directly on your device.
If you choose to participate in the Map Share program, your map corrections are shared with other users, and maps are automatically updated each time the GO 920T is docked with the computer.
The level of map sharing can be configured to accept all corrections, or only those verified by TomTom.
Even if you choose not the participate in the Map Share program at all, you can still benefit from other TomTom owners' corrections and automatically download Map Share updates. Also, the ability to change the mapping data directly on the GPS device is a powerful feature that allows drivers to correct mapping errors immediately instead of having to potentially wait years for mapping providers to update their database.
Just how powerful a feature is Map Share? According to Harold Goddijin, TomTom's CEO, "on average, by the end of 2008, if you drive anywhere for one hour with a Tele Atlas map enhanced by Map Share feedback, your route will be influenced by more than 20 corrections."
Figure 106: Map Corrections 1 of 2
Map correction can't be used to make major changes to the map. For example, you can't use the GO 920T's map corrections feature to add a completely new highway. But you can add or remove roadblocks, mark a one way street, change street names, and update turn restrictions and speed limit information.
Figure 107: Map Corrections 2 of 2
Map correction can also be used to add new POIs or update existing POIs.
Figure 108: Map Share Preferences
How much or little you choose to leverage Map Corrections & Sharing can be specified via the Map Share preferences screen, shown above.
Figure 109: Sharing Corrections
Map corrections you make can be shared with other TomTom users all the time, whenever you explicitly choose to do so, or never, depending on your own preference settings.
Figure 110: Quick Report Button
The Quick Report Button can be used to mark an area on the map you want to correct at a later time.
Figure 111: Disappointing Screen Brightness on TomTom's GO 920T
The GO 920T's screen isn't as bright as some other GPS units I've tested. Compared to the less expensive Garmin nuvi 660, TomTom's GO 920T looks washed out and dim. Even at 100% brightness (shown above), the GO 920T was less bright, and less readable in direct sunlight than competing units from Garmin and Magellan.
Figure 112: Measuring the GO 920T's GPS Signal Strength
GPS reception was excellent on the GO 920T, thanks in large part to TomTom's use of SiRF's high performance StarIII chipset. Throughout my testing, the GO 920T quickly acquired location data within a few seconds of powering on the device, and maintained position tracking even when driving in challenging urban environments.
The GO 920T's GPS receiver performed on-par with Garmin's nuvi 660, nuvi 880, and Magellan's Maestro 4250.
However, on occasion I did notice a considerable amount of "GPS drift" when sitting in a stationary vehicle. "GPS drift" is an situation where the GPS will show your position slowly "drifting" on the map, even if you are standing still in the same position. On the GO 920T, when starting out on a journey, or waiting at a traffic light, I noticed the map slowing turning in place, or drifting down the road slowly. As soon the vehicle began to move again, the GO 920T quickly snapped back into position and showed my accurate location on this map. This isn't a serious issue, but is more of a nuisance that TomTom should fix in future software updates.