Getting Lost With a Cellphone

...continuation...The ability to blithely make wrong turns without serious directional consequences is, of course, one of the hallmarks of PNDs — and a feature that allows me to ignore my wife’s beseechings and merrily proceed on my way without ever stopping to ask for directions. But when testing some cellphone navigation services, I’ve had to pull over and wait for the phone to download new instructions based on my new position (or worse, I’ve had to drive to an area where there’s cell coverage and then wait for instructions).

By comparison, a dedicated PND can reroute you in seconds without stopping — no cell signal required.

There are other disadvantages to using a cellphone as a digital road map. The speaker volume on most is inadequate to overcome road noise, and GPS tracking tends to drain the batteries of some phones. Moreover, GPS receivers in phones are often not as sensitive as those on dedicated navigation devices, so losing a positioning signal in, say, Manhattan, is not uncommon.

Phones also lack the gyroscopic sensors that many PNDs use to estimate a car’s position when a GPS signal fails, as in a tunnel. And there’s the screen issue: PNDs typically have 4-inch or larger screens; even the iPhone has only a 3.5-inch screen.

So for the moment, PNDs remain the most reliable means of directing you to your destination. But cellphones are catching up. Some, like the new Palm Pre, some BlackBerry models and phones based on Microsoft’s Windows Mobile or Google’s Android software, can multitask, allowing navigation to continue even while you’re chatting on the phone. Another approach is to store a complete set of digital maps on the phone so that when the cell signal disappears, your directions remain.

Garmin’s $99 Mobile XT software for smartphones comes on a tiny memory card that works on Windows Mobile phones, for example. Both Navigon and TomTom have adopted a similar full-download approach with their iPhone programs so that drivers don’t have to rely on a cellular network for route updates. To overcome some of the hardware shortcomings, TomTom will offer a car kit for the iPhone next month that includes a better GPS receiver and speaker built into a window mount.

Furthermore, as newer cellphones with more computing power are introduced, they won’t get lost in the hinterland as often. Phones also have a built-in feature most PNDs lack: two-way communication for updated listings, like service stations with cheaper gas and new restaurants, as well as concierge services like ordering tickets online...to be continued...