Glossary Portable GPS navigation systems

AC power cable included
Indicates whether the unit comes with an AC connector to power and charge the unit. This feature also allows you to use the unit inside your home so that you can program it in advance, research a route, or practice using it--even if the unit does not have a rechargeable battery.

Auto rerouting
Indicates how the navigation system informs the driver that they missed a turn and that it is calculating a new route. Some systems show this on screen, some tell the driver audibly, some combine the two, and others provide no indication at all.

Biking or walking mode
Adjusts the routing to account for the freedom, and limitations, of traveling by bike or foot. The system may avoid highways or disregard one way street signs in this mode.

Bluetooth hands-free calling
Allows user to make and receive hands-free telephone calls using the unit's internal speaker, microphone, and screen. Automatically quiets directions while call is being made. Can display user's telephone book, and shows caller ID on the screen. Can also dial phone numbers of point of interest locations. Requires a Bluetooth-compatible telephone.

Dimensions H x W x D (in.)
The measured height, width, and depth of the unit, measured in inches and rounded to the nearest tenth.

Dynamic database gray-out letters
When typing an address the unit will gray out letters that are not possible to complete a word; for instance, if you typed in XYLOPHO, the system would grey out everything but N (because that would be the next letter in the word xylophone) and whatever other few letters might complete the word.

FM transmitter
Allows users to listen to spoken navigation system directions through their car stereo. If the unit is equipped with an MP3 player, music can also be played through the stereo.

Gas prices capable
Indicates if the nav system is capable of providing gas prices near the driver's current location out of the box.

Internal battery
Indicates whether the unit has a built-in rechargeable battery, which allows the user to navigate without plugging into a car's 12-volt power outlet. Built-in batteries are also handy if you want to preprogram a route from your living room, or for bringing the system along on a walk.

iPod interface
The ability to connect an iPod to the navigation system, allowing the user to control the iPod with the unit's touch screen. The purchase of an additional cable is usually required.

Lockout safety mode
Allows the user to lock system controls while driving to reduce the risk of driver distraction caused by interaction with the system.

Memory storage
Indicates how the unit stores files for audio, photo, and video content. Often maps for different countries are accessed using SD cards, too.

MP3 player
Means the device can store and play pre-loaded audio files. Capacity varies by unit. Most navigation units have SD card expansion slots for file storage.

Multi destination routing
Allows a user to add multiple stops along a programmed route.

Photo viewer
The ability to store, display, sort, and put together albums of previously loaded photographs.

Pre-loaded map database
This is the map coverage provided by the navigation system that is available to use right out of the box. All tested units include at least the 48 contiguous United States. Many also include Alaska, Hawaii, Canada, and Puerto Rico. Additional maps for travel abroad can be purchased from some manufacturers, typically for $150 to $300.

Price
An approximate retail price.

Screen size (in.)
The measured diagonal length of the display screen measured in inches and rounded to the nearest tenth on an inch.

Spoken street names
Commonly referred to as "Text-to-Speech," this helpful feature is the ability to pronounce proper street names. For example, a system with this feature would say, "Turn right on Truman Avenue" rather than, "Turn right in 500 feet." Spoken street names allows the driver to confirm directions with street signs without looking at the screen.

Traffic capable
Indicates whether the navigation unit has the ability to receive and display real-time traffic conditions. "Opt." indicates that an additional receiver is needed. Most traffic-capable systems require a subscription service.

Traffic receiver included
That means that the unit comes with necessary hardware to receive traffic data provided from a subscription service.

Trip computer
The ability to display data about a trip, such as miles traveled, current speed, average speed, time stopped, time driving, and total time.

USB
Allows you to connect the unit to a personal computer using a USB connection. This is handy for multimedia data transfer, as well as software and map upgrading.

Video player
Enables the user to play movies or videos pre-loaded from their computer. Navigation features are typically disabled when this feature is in use.

Weather capable
Indicates if the navigation system is capable of providing weather reports out of the box.