TomTom's IQ Routes Prove Americans Aren't Speed Demons

It's amazing what technology can discover these days. Like how Americans really aren't the speed demons they are made out to be. Believe it or not, we aren't being sarcastic. TomTom has just published a report that utilized lots of Speed Profiles data in order to provide the first fully detailed view of which interstate highways are the fastest and slowest in the United States.

The results were nothing short of stunning in our opinion, as we tended to believe (much like everyone else, we think) that most drivers sped on Interstates. The report found that while the average travel speed exceeded the speed limit in a few places (understandable!), overall, drivers tend to be mindful of the posted limits and obey then. The data only calculated speeds when traffic was free-flowing, which keeps the numbers from being skewed by wrecks and rush hour jams that would make us all seem like saints.

What's interesting is that our own experiences don't mimic this. Almost always we have found drivers going right at, or slightly over, the posted limit. Evidently that's not the norm. For those wondering, Speed Profiles is a historical database of numbers gathered by Tele Atlas, which is generally used to help personal and professional fleet drivers find the best routes. It's integrated as IQ Routers within TomTom GPS devices, and it aggregates, anonymously, the actual speeds that millions of GPS-enabled drivers have traveled over the last two years. Read on for the exact details about who goes slowest, who goes fastest, and which Interstate has earned the nickname"America's autobahn."

U.S. Drivers Not The Speed Demons You May Think

Data from GPS users show drivers stay within speed limit range on most major U.S. highways; the fastest highway, "America’s Autobahn," is on I-15 in Utah and Nevada, while the slowest road is in Washington D.C.

Concord, MA – January 21, 2010 – TomTom, the world’s leading provider of navigation solutions and digital maps, today revealed the first fully detailed view of which interstate highways are the fastest and slowest in the United States. Although the average speed on some U.S. roads slightly exceeded the speed limit, data from GPS users show that, overall, drivers tend to stay within speed limit range on most major U.S. highways.

The results were calculated using data from Speed Profiles™, the historical speed database from TomTom’s map business unit Tele Atlas that helps personal and professional fleet drivers find the best routes. Speed Profiles is integrated as IQ Routes™ on TomTom devices. It aggregates, anonymously, the actual speeds that millions of GPS-enabled drivers have traveled over the last two years to provide the most accurate view of historic speeds available.

Data were organized to show the average speeds on interstate highways and to reflect only free-flow speed data, or average speeds when there is no traffic present. When compared to a database of posted speed limits, the results indicate that the average U.S. driver stays within the speed limit range on most urban and rural interstate highways:

- Even drivers in the fastest states tend to stay within the speed limit range. Across all interstate highways, Mississippi has the fastest roads, with average speeds of just over 70 MPH and posted speed limits ranging from 65-70 MPH. New Mexico (70 MPH actual average, 70-75 MPH posted speed limits), Idaho (70 MPH actual average, 65-75 MPH posted speed limits), Utah (70 MPH actual average, 65-75 MPH posted speed limits) and Alabama (70 MPH actual average, 60-70 MPH posted speed limits), round out the top five states with the fastest interstates in the country;

- Famous worldwide as a road network where drivers can go as fast as they like, Germany’s Autobahn has speed limits in some areas, but drivers typically travel over 100 MPH in unregulated spots. Where is America’s Autobahn? Our fastest road is on I-15 in Utah and Nevada, with speeds averaging 77.67 MPH, although some spots on that highway allow 80 MPH;

- The nation’s fastest area is in the middle part of the country. Seven of the top 15 states with the fastest highways are in that area. The average speeds on roads in Mississippi, Nebraska, Kansas, Iowa, Idaho, Alabama and Missouri exceed 67 MPH; the average posted speed limits in those states is 70 MPH;

- Speeds on single interstate highways that span a number of states, such as the

I-95 route running from Northern Maine to Southern Florida, differ dramatically depending on where you are. Along that highway, the fastest section is in South Carolina; the slowest sections are in Virginia, New York, New Jersey and Connecticut.

- Findings for the Washington D.C. area echo results found in TomTom’s recent study of the most congested traffic spots in the U.S. (see Washington D.C. has the slowest average MPH on its interstate highways, at 46 MPH. After Washington D.C., the states with the slowest interstate average MPH are Hawaii (53 MPH), Delaware (61 MPH), Rhode Island (63 MPH), and Oregon (63 MPH).

The Speed Profiles database currently covers 85,000 miles of interstate highways in the United States. To see lists of the top 20 states with the highest MPH averages, maps of the fastest and slowest highways in the U.S. and for further information, go to
Via:  TomTom
gibbersome 4 years ago

Very interesting, though it's important to note that speed limits near cities tend to be 5-10 MPH lower than elsewhere on the interstates. Also, they didn't show any states that have a strict 65 MPH speed limit, such as New York.

gibbersome 4 years ago

Oops, actually saw that they accounted for traffic flow and urban/rural posted speed limits. Haha, I guess the recession must be impacting people's driving behavior, no one wants a speed ticket.

Selks 4 years ago

Wish canada would increase their speed limits. Divided Highways are 100km/hr or 62.1371192 miles / hr. But the again we have accidents on a daily basis as it is.

JoelB 4 years ago

Selks: Which part of Canada are you talking about? Here in Alberta divided highways are generally 110 km/h.

kid007 4 years ago

Highways here in michigan are awesome, you do your 80-85 and no one bugs you :) that is my daily commute

rapid1 4 years ago

Lol yeah one thing they don't take into account for Ga. is thats the general speed everywhere highways rural roads. That also seems low to me, especially on the highways (over 2 lanes which is 90%). Anywhere in Atlanta the fast lane or the multi lane most are doing 80 at least.

realneil 4 years ago

I lived in California for years. Driving there amounted to trying to keep up on all of the roads. If you drove the speed limit, people ended up giving you the one fingered salute as they blasted by you at speed. I found myself driving faster as a result. I added 10MPH to any and every posted limit as a rule, except in housing areas and school zones. The cops NEVER bothered you at 10-over in California.

I've since moved to rural Virginia and people seem to take it slower here. They don't yank into your lane at the last possible second causing you to SLAM on your brakes. They allow the other guy at a four way stop to go before themselves. Overall they are far more considerate drivers and it has affected my driving as well. I don't mind doing the speed limit anymore. I know I'll get there eventually,............It's much more relaxing to me.

Soupstyle 4 years ago

It is really more that people with GPS's don't speed!

Those of us who have good senses of direction seem to also be the ones with the lead feet, lol.

BobSalawalatski 4 years ago

I think this has to do with inaccurate speedometers.

Virtually all speedometers indicate a speed higher than your actual speed by anywhere from 1 to 7% right from the factory. Manufacturers understand that speedometers can't be perfect, so they make them a little on the optimistic side so people don't speed (or get into an accident) and then blame them. Add to this the fact that most people don't regularly check their tire pressures, and it makes them that much more off. (Running with low tire pressure effectively decreases the radius of the wheel, which means the wheel's rpm must increase to travel the same speed as with normal tire pressure.)

GPS, on the other hand, measures your speed from stationary points outside of the vehicle, making it much more accurate, even if it can't get your exact position just right.

So when you're on the highway and it seems like you and everyone around you is doing 5 over, the reality is you're probably right around the limit, or possibly a little under it.

gibbersome 4 years ago

Great point on the tire pressure.

Also, speedometers have a little variation when they come out of the factory, so manufacturers set them a little higher so people don't blame the car maker for speeding tickets. It decreases the possibility that the speedometer will be under-read.

I agree, with all the points considered, GPS would be much more accurate way of measuring speed.

rapid1 4 years ago

Yeah tire pressure can actually effect quite a few things. The biggest probably being gas mileage and wear on the wheels as well as breaking to.

Gonzobot 4 years ago

The issue isn't that the AVERAGE speed is too high or low. The issue is the lone jackass doing a hundred-fifty while eating a donut and texting his mom. Useless information is useless.

Post a Comment
or Register to comment