GPS navigation systems: Choosing the right one

If you're heading out on a road trip this summer, a GPS navigation system is a good companion. A portable until is easy to live with and more affordable than built-in factory systems.

Segment leaders Garmin, TomTom, and Magellan continue to dominate our Ratings,with easy to use, intuitive interfaces and reliable directions. To make shopping easier, we've broken down portable GPS navigators into three categories: basic, traffic optional, and traffic ready. Determining the features you want and the amount you want to spend will help you to select the category that is best for you.

Basic. These are no-frills devices, ideal for those who don't need a lot of bells and whistles like Bluetooth connectivity for hands-free cell-phone use and MP3 players. The least-expensive models in this category generally have 3.5-inch screens and are some of the more compact models, which can make them even more appealing to frequent flyers. As a bonus, prices start at about $100, and even lower prices can be found with sales and incentives. Basic models with 4.3-inch-wide screens are generally the more expensive ones in this group.

Price: $80 to $300.

Traffic optional. These are ideal if you're not sure you need traffic info now, but might want to add it later. Keep in mind that adding traffic later on means buying a separate receiver, which can cost up to $200. Models in this price bracket often also add a few key features, like spoken street names. The added features vary by brand; check our Ratings for the ones important to you.

Price: $100 to $300.

Traffic ready. A top-of-the-line, premium unit usually comes traffic reporting ready with a built-in or included external receiver, but may require a separate subscription for traffic info. They include the features we recommend, plus add extras like a music and video player, Bluetooth, FM transmitter, and wide screen.

Price: $120 to $430.