If you’re shopping for a GPS navigation system, you’ll find there are a lot of choices. It’s often hard for a first time buyer to know what to look for when comparing different models in their price range. This article provides a few tips to help get you started.

First, let’s focus on the features that matter most:

  • map coverage, accuracy & detail
  • quality & speed of route calculations
  • map storage capacity
  • ease of use

Then we’ll wrap up with a discussion of other features that may or may not make much difference for the average user.


Map Coverage

Most navigation systems sold in the United States include maps for at least the 48 contiguous states. Many also include Canada, Alaska, Hawaii, Puerto Rico, and the US Virgin Islands.

Make sure maps are included for areas you’re likely to visit.

Map Accuracy & Detail

Maps used by navigation systems are usually at least a year or two out of date. If you travel on roads with recent changes, you should look to see if the changes are included in the navigation system’s maps.

A few things to check:

  • new freeway exits
  • roads for new housing developments
  • roads closed to reduce through traffic

If you visit rural/recreational areas, you may want to see if maps include private roads, dirt roads, and forest service roads that you might have a need to use.


TIP: Garmin allows you to view their detail maps from the cartography section of their web site.

Route Quality

Route quality can be difficult to compare, but it’s one of the more important features in everyday use. Poor quality routes include unnecessary turns and detours or can take you on roads you want to avoid.


Better systems allow you to choose the type of route you want:

  • faster time
  • shorter distance
  • favor (or avoid) use of freeways, minor roads, etc.

If you can’t take a test drive with a system, look on the web for reviews and discussion topics where users share their actual experiences with a particular model. Having a feature doesn’t mean it works well.

Speed of Route Calculations

Calculation speed is especially important in situations where you’ve missed a turn. Slower systems may not be able to recalculate your route in time to catch the next turn and get you back on track.


Better systems take only a second or so to recalculate. Slower systems can take 10 – 20 seconds (or more) to figure out a new path. In some situations, you may pass a turn it was planning to take before it finishes recalculating the route.

If you have a chance to test drive a system, you should deliberately miss a few turns and see how well the system responds.

Map Storage Capacity

Many newer navigation systems come pre-loaded with a full set of maps, but don’t rule out models with less storage capacity if the areas you drive in are fairly predictable.

Frequent travelers who visit a lot of different cities should get a system with enough capacity to load a full set of maps. People who usually stay in a particular region will probably be satisfied with 100MB – 200MB for map storage.

Ease of Use

Other features can add up to make a system a lot easier to use. Here are a few of the more important ones:


  • spoken directions guide you through turns and let you keep your eyes on the road
  • choose a screen size that’s easy to read, but not too large for the vehicle(s) you’re planning to use it in
  • a touch screen or keyboard makes it easier to enter destination addresses
  • simple menus save time and frustration
  • color screens make it easier to view map details

Other Things to Consider

A lot of new users focus attention on accuracy values stated by the manufacturer. In practice, you’ll probably find that GPS position accuracy is adequate with any newer GPS model. What usually counts more is how quickly the system processes position and map data to keep your navigation instructions up-to-date. Extra accuracy doesn’t do much good if the system is too slow to make use of it.


If you drive a lot in “urban canyons”, you may want a model with dead reckoning capability. This feature continues to estimate your position in situations where the system has lost GPS reception.

Finally, take some time to look around the rest of this site. You’ll find additional information on many of the features mentioned in this article.

Good Luck,
The RoadmapGPS Team

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