Choosing the best GPS navigator for yourself, or for a holiday gift, can be a daunting task. New products, features, and even technologies emerge every few months. As a result, models come and go, and prices change continuously. With that in mind, we created this Consumer Reports Value Index™ to help shoppers to get the best GPS for their money. (In addition to this guide to traffic-ready navigators, we built a Value Index for basic navigators and traffic-optional navigators.)

If traffic information is a key factor in your purchasing decision of a  portable navigation device (PND), we feel your best investment is in a GPS device that can satisfy that need right out of the box. But as this interactive chart demonstrates, not all GPS navigators are created equal.

To make this index, we combined our latest GPS ratings with approximate retail pricing, then analyzed the value proposition for the devices. Consider this a snapshot in time.

More than just measuring the value in making the purchase, we focused this analysis on three-year ownership costs. The costs presented here reflect the expense for a traffic subscription, if required. This was no small task, as every company has its own plans, and those vary between product lines. Where there were options, we chose the subscription package that would lead to the lowest costs for three years. Our figures reflect three-month and one-year free deals offered to new owners, when applicable. By taking this approach, we are able to reveal the real-world cost for traffic services and compare GPS navigators on an equivalent basis.

The interactive graphic below plots our overall Ratings score versus the three-year cost based on an approximate retail purchase price plus the cost of traffic subscription, with a tri-colored background showing the “value zones,” those regions that represent a high, medium, and low value. Products on the upper right side of the chart offer better values than those further to the left and bottom.

Each featured GPS unit to the right is listed according to our value index. Roll your cursor over the product name to see that model indicated in the scatter chart, along with its approximate retail price, the cost for three years of traffic service, and a direct link to its model page (available to online subscribers) for more information.

The clear standout product is the Garmin Nuvi 265T, a CR Best Buy, along with the widescreen-version, the Nuvi 265WT. The lone high value in this category, this duo is a full-featured with some useful features, like spoken street names, Bluetooth hands-free calling, traffic receiver, and free traffic services. That’s right, free traffic. And therein lies the true cost benefit for this highly rated model. The one catch is that the traffic service comes with text-based advertisements. In our testing, we found that the ads are not too intrusive and may be worth the trade off to eliminate a monthly fee.

If you want traffic information, but refuse to accept ads on your dashboard, the options are to choose a device that requires a subscription service or look to the Navigon offerings. Our ratings include several Navigon models with free-lifetime traffic.

Generally, Navigon devices trail Garmins for ease of use, touchscreen sensitivity, and overall refinement. But the latest units have narrowed the gap, such as the 2200T and the 7200T. Priced at $230, the 2200T is essentially a basic navigator with traffic. The screen size is 3.5 inches and map coverage just 48 states, however it does have a few features often found on pricier units. The 2200T includes helpful spoken street names, reality view, and lane assist. If found for less money, the value story for this model would improve significantly.

The stories vary for the lesser-value models, reaffirming the importance of checking the full GPS navigator ratings. For instance, the Garmin Nuvi 760 is a very good unit, limited by its midlevel price and a low, $60 one time subscription fee. Otherwise, this feature-rich model is quite appealing. On the other hand, the Magellan Maestro 3250 sees its value elevated by an entry level price of $200, but still requires a $40-a-year subscription fee. While this device may appeal for its low purchase price and most annual fees, in the end, it is just an average-performing navigator. It pays to look closely at both the how the device scores overall in our testing and its subscription rate.

Ultimately, most tested traffic-ready GPS devices proved to be low values because the built-in ability to receive traffic (without purchasing an optional receiver) tends to be on mid-level and premium models. Getting the traffic service often means buying a unit with many extra features not necessarily related to guidance.

Bottom line
In a survey of GPS owners conducted by the Consumer Reports National Research Center, traffic info drew the greatest interest among GPS features. About half of respondents whose units lacked traffic capability said they want it. But almost half of those who had it never used it.

Carefully consider the long-term value of traffic information, remembering that in most cases the information is no more complete or timely than local radio traffic alerts. And the information varies little between units. However, GPS units with traffic can allow you to find the best route to your destination automatically to avoid any delays.

Choosing a model with free traffic or a free trial period will enable you to live with the service and see if its benefits warrant an annual subscription. Many GPS companies offer annual and lifetime plans, allowing for some savings. (Learn more about GPS traffic services.)

Before making the big decision, review our detailed Ratings and model overview pages to better understand the differences between units. We updated both today, adding more new units in time for holiday shopping.

Remember: As prices change, so does value. Do your homework and make sure you not only get a great price, but also buy a great GPS device.

Value Index is a Beta project, and we have applied this concept to super-zoom digital cameras, flat-panel TVs, and basic navigators recently. Let us know your thoughts on whether this type of tool is helpful by using the Comments below.

—Jeff Bartlett

For more information on portable automotive GPS navigation systems, see our Ratings and buying advice and watch our video guide. If you're interested in going off the beaten path, See our handheld hiking GPS buying advice and Ratings. Discuss GPS devices in the forums.