If you tap Yes, enter an arrival time and the system can calculate if you will arrive on time based on your current location. The One has the ability to calculate directions by fastest route, shortest route or avoiding motorways.
There's a Find Alternative function if you're not a fan of the prescribed route or you run into some traffic along the way. For example, you can have the One recalculate the route altogether, or if you run into roadworks, it will plot a course around them.
You have the option of viewing maps in 2D or 3D view. There's also a night mode that changes the colour of the maps for better night-time viewing. You can choose to have driving directions presented as text or images. For the highly organised, you can even get a running demo of your route before you hit the road.
The main driving view will give your current position, the name of the next major road, the next instruction, information about your trip and signal strength. In addition, you can zoom in and out of maps, using the plus and minus signs in the upper left- and right-hand corners of the screen.
Of course, in addition to the visual prompts, you get spoken, turn-by-turn directions, and you can choose different voices if you don't like the default. Unfortunately, the One does not support text-to-speech functionality, which speaks the actual street names rather than generic directions.
As you become more accustomed to the One and to navigation systems in general, there is an option to add TomTom's Plus services, including real-time traffic information and speed camera warnings. Just be aware that there is a subscription fee, and you will need a Bluetooth-enabled, GPRS phone to connect to the service.
From a cold start, the unit's SiRF StarIII receiver quickly locked on to a signal in about a minute. Some systems can take up to five minutes or more to acquire a satellite fix, so we were impressed with the One's performance.
The One accurately pinpointed our position as we drove around familiar streets. We also entered the address of a friend's place and the One got us there with no problem. The voice prompts were loud and clear, and the unit also has a function where it will automatically increase the volume the faster you go, based on the assumption there's more road noise in the car -- a nice touch.
Edited by Jason Jenkins
Additional editing by Kate Macefield