The 10 US cities with the absolute worst traffic

AP Photo/Jae C. Hong

The average US commuter spends 42 hours stuck in traffic a year, according to a report by the Texas Transportation Institute.

But naturally some cities are worse than others when it comes to commuting. TomTom, a navigation and mapping company, ranked which US cities have the most traffic congestion in its 2017 Traffic Index.

After collecting data over a nine-year time span, TomTom measured the extra travel time experienced by drivers over an entire year. TomTom assessed 189 cities overall and gave each a congestion score out of 100.

Here are the most congested cities in the US:

10. Boston received a score of 28%, a 3% increase from the year prior.

9. Washington D.C. barely edged out Boston with a score of 29%, a 3% increase from the year prior.

8. Honolulu received a score of 29%. That's the same as Boston, but Honolulu has more congestion in the morning. Honolulu's traffic score was the same as the year prior.