GPS

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. May require a fee-based subscription.

Historic traffic data

Databases of past traffic patterns can inform route planning, predicting routine flow changes such as rush-hour congestion. This feature does not require a traffic receiver or subscription. It can add intelligence to trip routing, but does not reflect current, real-world conditions.

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.

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.

Dynamic database gray-out letters

When typing an address, the unit will gray out letters that are not possible combinations to complete a word. For instance, if you typed in XYLOPHO, the system would gray out everything but N because no other letters would combine to form a proper word in the database.

Multi-destination routing

Allows a user to add multiple stops along a programmed route.

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.

Traffic antenna

Indicates the type of antenna needed to receive traffic data. Common types include an internal receiver, a receiver integrated into the power cord, or an additional external antenna that adheres to the windshield.

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.

Auto rerouting indicator

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.

WiFi/Cellular connectivity

Connectivity enables devices to access data from Internet sources, and in limited applications, devices can interact with a PC or other GPS units.

Music player

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.

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.

Weather capable

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

Location help

Provides current location, often using a combination of street intersection and GPS coordinates to aid in directing help. Better models also provide contact information for the nearest emergency services

Reality view

Realistic depiction of highway junctions with lane specific visual directions to inform a driver in advance of their next maneuver.

Lane assistance

Indicates the appropriate lane for the driver to travel in order to execute their upcoming maneuver.

Exit guide

Handy for travelers, this feature tells you what services are available exit by exit on major highways. Touch an icon on the screen, and up comes a list of gas stations by brand, along with hotels, dining options, and car-repair facilities, all within a mile of the off-ramp. In addition, some devices will allow you to search for points of interest along a plotted 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 $50 to $100.

Trip log

Function varies, though better units track trip progress by recording data on distance traveled, average speed, and time spent that can be recalled later. This information may appeal to business travelers for monitoring expenses. Some units will indicate on the map if roads had been traveled previously.

Dimensions HxWxD

The height, width, and depth of the unit measured in inches and rounded to the nearest tenth.

Traffic receiver

Indicates if the GPS navigator includes a traffic receiver, if the receiver is optional, or if the navigator is not traffic capable.

Carrying case

A carrying case can protect the unit when stored, transferred, and while traveling.

Weight

Measured weight of just the unit (excluding mount) in ounces rounded to the nearest tenth.

Replaceable battery

A rare feature, some units have a removable battery. Should the original battery expire, the ability to replace it could extend the functional life of the portable device, without depending on a plug-in power source for operation. A value of NA indicates that the unit does not have an internal battery.

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.

Traffic receiver price

The cost of the accessory required to receive traffic data. The receiver is typically an external wire antenna or integrated into the power cord.

USB cable included

A USB cable is used to connect the portable navigation device to a computer for updating maps and transferring data, including address, custom points of interest, music, and firmware updates.