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June 7, 2007

Garmin vs. Magellan vs. TomTom: Which GPS Picks The Best Routes?

Garmin vs. Magellan vs. TomTom

All the bells and whistles aside, what really matters on any GPS is the quality of the maps, and how well the GPS figures out the best way to get from point A to B.

I put the TomTom ONE XL, Magellan Maestro 4050, and Garmin nuvi 680 to the test. Which GPS has the best routing engine? Read on.

The single most common complaint I hear is "the GPS took me on a crazy route that I would never have chosen and was not the best/shortest way."

Arguably the most critical components of any turn-by-turn GPS navigation system are the routing engine and map accuracy. The routing engine is the software on a GPS that decides which route the unit should choose to get from point A to point B. Many people falsely assume that simply having the same maps on two GPS devices will result in the same routing choices. Not so, as there is a great deal of math and decision-making involved when calculating the "best" route.

Not surprisingly, this also one of the most difficult and complex aspects for GPS manufacturers to get right, and is the aspect of GPS navigation that is least well understood by consumers.

Confusing Street Signs

The two largest mapping data providers are NAVTEQ and Tele Atlas . NAVTEQ is more accurate and complete in North America, so it's preferable to buy a GPS that uses NAVTEQ rather than Tele Atlas (as of this writing). (for more detailed information on both NAVTEQ and Tele Atlas, check out "NAVTEQ vs. Tele Atlas, Which one is Better?")

However, there is a lot more to a routing engine than just the mapping data provider. How a given GPS will determine the "best" route is the result of not only the mapping data, but also how many additional data points, or attributes, are factored into the equation. For example, are certain roads closed after hours or on the weekend? What is the average rate of speed for a given road? Statistically speaking, more accidents happen when making left turns as opposed to right turns -- is the GPS unit factoring that into the route? Each company takes all this data and compiles it in different ways, making unique decisions about what data is more important than others. The number of attributes used varies depending on how much money the manufacturer is willing to spend on their mapping data. For example, a full NAVTEQ map database that includes all available attributes can cost the manufacturer twice as much as a basic set of attributes.

All Magellan and Garmin GPS units use NAVTEQ mapping data, while TomTom uses Tele Atlas. Magellan's Maestro unit ships with 2007 NAVTEQ maps pre-installed, while the Garmin nuvi's NAVTEQ maps are several years old, (although Garmin is planning to release updated maps within the next month or two). TomTom newly updated Tele Atlas maps are also from 2007.

In order to find out which GPS has the best mapping and routing capabilities, I tested the latest and greatest models from Magellan (Maestro 4050), Garmin (nuvi 680), and TomTom (ONE XL). Note that the TomTom ONE XL I tested is the newest version and has TomTom's newly updated maps installed on it..

To accurately test each of the units, I entered three different trips of varying distance in three different regions of the United States.

Our first test took us along the Northeast, starting in Southbury, CT and ending in New York City:

ROUTING TEST #1
WINNER: Garmin
Start: 14 Oak Tree Road, Southbury CT. Destination: 135 Central Park West, NY, NY
Magellan Maestro 4050
Garmin nuvi 680
TomTom ONE XL

0.1mi Main St S
0.1mi US-6/Main St N
0.1mi W I-84
14mi W I-84
4.1mi W I-84
6.6mi Exit 20/White Plains/I-684/NYC
0.1mi White Plains/I-684/NYC
10mi South I-684
16mi South I-684
9.1mi W Cross County Pkwy
2.4mi W Cross County Pkwy
0.3mi W Cross County Pkwy
2.1mi Exit 2/NYC/Saw Mill
0.2mi Saw Mill River Pkwy South
2.0mi S Rt-9a/Henry Hudson Pkwy
10mi Exit 79 St
0.1 Roundabout W.79 St
0.3mi Broadway
0.3mi W. 74 St
0.4mi Central Park W
* 0.1mi Arrive at 135 Central Park West

300ft Main St S
300ft Main St N
0.1mi Keep right onto I-84 W to Danbury
14mi Keep left on I-84 I-84 W
4.1mi Keep right onto I-84 W to NY State
6.5 Exit 20 right to I-684 to New York City/White Plains
0.1mi Keep left onto I-684 to New York City/White Plains
28mi Exit 1 left to Hutchinson Pkwy to Whitestone Br
9.1mi Exit 15 left to Cross County Pkwy to George Washington Br
2.7mi Keep left on Cross County Pky W
2.0mi Exit 2 left to Saw Mill Pkwy South to New York City
0.2mi Keep left onto Saw Mill River Pkwy South
2.0mi Keep right onto Henry Hudson Pky South
10mi Right to 79 St Boat Basin
500ft Take roundabout to 3rd exit
400ft 3rd exit to 79th St
0.2mi Right on Broadway
0.3mi Left on 74th St
0.4 Right on Central Park W
120ft Arrive at 135 Central Park W on right

40yd Main St S
100yd Main St N (US 6)
240yd 84 WB
14.1M Bear left onto 84 WB
4.1M Bear right onto 84 WB
3.2M Bear left onto 84 WB
3.4M Rt. 20 White Plains
250yd 684 SB
10.9M Saw Mill Pkwy
0.55M Continue Saw Mill Pkwy
13.2M Bear left Yonkers
4.7M 22 Thruway
250yd 87 SB
0.35M 87 SB
16:5M 7 Trenton
400yd 95 SB to 1
0.50M 95 SB to 1 Lower Level
0.55M H Hudson Pkwy
210yd 9A SB Downtown
0.40M H Hudson Plwy
4.6M Exit Boat Basin
♦220yd - Roundabout W 79th St
275yd Riverside Dr
0.35M W 72nd St
0.60M Central Park West
♦130yd - Arrive 135 Central Park W

Total: 80 miles / 1hr 29 minutes
80 miles / 1 hour 19 minutes
79.2 miles / 1 hour 30 minutes

Magellan's Maestro 4050, Garmin's nuvi 680, and TomTom's ONE XL all get us to our destination address, but the Garmin nuvi chooses a slightly faster route, provides more detailed navigation instructions, and is also the only GPS to announce what side of the street our destination address is on.

TomTom's ONE XL faired the worst in this test, routing us in such a way that the destination address is actually on the left side of the street. We would then either have to make an illegal U-turn or go around the block to arrive at 135 Central Park West on our right. TomTom also has less detailed navigation prompts than the Magellan Maestro 4050. TomTom also reports distances in yards instead of feet.

Yahoo! Maps (not shown in the table above) chooses a route identical to Garmin's route, but estimates the trip will take 3 minutes longer (1 hour 22 minutes) than Garmin estimates. Google Maps also chooses the same route as the Garmin nuvi.

So far Garmin's nuvi is in the lead in our routing battle. However, sometimes a GPS that routes perfectly well in one area can perform terribly in another region. Our first test used a trip that was approximately 80 miles in length and took us from Connecticut to New York City.