(March 8, 2011) KIRKLAND, Wash. (PRNewswire) — A new study by INRIX found what millions of Americans drivers caught in big city traffic every day already know — the U.S. is a nation of gridlock.

INRIX, a leading provider of traffic and navigation services, has released its 4th Annual INRIX National Traffic Scorecard revealing gridlock and longer commute times returning to America's roads. Traffic congestion increased nationwide for 11 consecutive months in 2010 with drivers experiencing increased traffic congestion nearly every hour of the day. 

"America is back on the road to gridlock," said Bryan Mistele, INRIX president and CEO.  "Population growth combined with increases in interstate commerce spurred by economic recovery are fueling these increases.  With only 150,000 new jobs created in our nation's urban centers last year, we can expect even worse gridlock when the 6 million jobs lost in the recession return to the nation's cities."

Despite only modest employment gains in 2010, drivers are experiencing an average 10 percent increase in travel times.  If unemployment drops to 7 percent by 2012 as some economists' predict, 9 million more daily work trips will jam our nation's road network. 

In fact, 70 of the Top 100 Most Populated Cities in the U.S. are experiencing increases in traffic congestion. Nine cities already have surpassed their 2007 peak. By analyzing traffic on major highways in the nation's 100 largest metropolitan areas in 2010, the Top 10 most congested U.S. cities are:

   1. Los Angeles: On Thursday at 5:30 p.m., the average trip takes 71 percent longer than normal
   2. New York: On Friday at 5:15 p.m., the average trip takes 47 percent longer than normal
   3. Chicago: On Friday at 5:15 p.m., the average trip takes 41 percent longer
   4. Washington, D.C.: On Thursday at 5:30 p.m., the average trip takes 51 percent longer than normal
   5. Dallas: On Friday at 5:15 p.m., the average trip takes 36 percent longer than normal
   6. San Francisco: On Thursday at 5:30 p.m., the average trip takes 63 percent longer than normal
   7. Houston: On Friday at 5:15 p.m., the average trip takes 33 percent longer than normal
   8. Boston: On Friday at 5:30 p.m., the average trip takes 33 percent longer than normal
   9. Philadelphia: On Friday at 5:15 p.m., the average trip takes 29 percent longer than normal)
  10. Seattle: On Thursday at 5:15 p.m., the average trip takes 49 percent longer than normal

These cities account for more than half of our nation's traffic congestion with 9 of the top 10 cities experiencing modest increases in traffic congestion in 2010 (Chicago being the lone exception).  Of these cities, New York, San Francisco and Philadelphia experienced increases of almost 20 percent attributable to rebounds in the technology, healthcare, manufacturing, freight movement and services sectors that are the backbone of these local economies.  

In comparing U.S. and European cities, Los Angeles' freeway system is more congested than that of any other city in the U.S., U.K., France, Germany, Belgium and the Netherlands.

Nationwide, Americans traveling the nation's worst traffic corridors experience up to 80 hours of delay annually on the afternoon commute alone.  Over 500 miles of roads were congested 25 hours a week or more, nearly 200 of those miles were congested 40 hours a week or more — higher than any previous year.

Of the 341 corridors of at least 3 miles long that experience heavy traffic congestion every day, the Top 10 Worst U.S. Traffic Corridors were:

   1. New York: An 11-mile stretch of I-95 SB (NE Thwy, Bruckner/Cross Bronx Expys) from Conner St to the Hudson Terrace exit that takes 43 minutes on avg. with 30 minutes of delay
   2. Los Angeles: A 20-mile stretch of the Riverside Fwy/CA-91 EB from the CA-55/Costa Mesa Fwy interchange to the McKinley St. exit that takes 57 minutes on avg. with 37 minutes of delay
   3. Los Angeles: A 13 mile stretch of the San Diego Fwy/I-405 NB from I-105/Imperial Hwy interchange through the Getty Center Dr. exit that takes 41 minutes on avg. with 28 minutes of delay
   4. Chicago: A 16-mile stretch of I-90/I-94 EB (Kennedy/Dan Ryan Expys) from the I-294/Tri-State Tollway to the Ruble St. exits that takes 49 minutes on avg. with 32 minutes of delay
   5. Los Angeles: A 15-mile stretch of the Santa Monica Fwy/I-10 EB from CA-1/Lincoln Blvd. exit to Alameda St. that takes 42 minutes on avg. with 28 minutes of delay
   6. New York: A 16-mile stretch of the Long Island Expy/I-495 EB from the Maurice Ave. exit to Mineaola Ave./Willis Ave. exit that takes 45 minutes on avg. with 29 minutes of delay
   7. Los Angeles: A 17.5-mile stretch of I-5 SB (Santa Ana/Golden St Fwys) from E. Cesar Chavez Ave to Valley View Ave. exits that takes 45 minutes on avg. with 30 minutes of delay
   8. New York: A 10-mile stretch of I-278 WB (Brooklyn Queens/Gowanus Expy) from NY-25A/Northern Blvd. to the NY-27/Prospect Expy. Exits that takes 37 minutes on avg. with 24 minutes of delay
   9. Pittsburgh: An intense 3-mile stretch of Penn Lincoln Pkwy/I-376 EB from Lydia St. to the US-19 TK RT/PA-51 exit that takes 17 minutes on avg. with 13 minutes of delay in the morning peak period
  10. Los Angeles: A 13-mile stretch of the San Bernadino Fwy/I-10 EB from City Terrace/Herbert Ave. to Baldwin Park Blvd. that takes 37 minutes on avg. with 24 minutes of delay

If you happen to drive any of the Top 10 Worst Corridors during rush hour you spend more than one month per year (four work weeks)  stuck in traffic and could ride a bike faster than you could drive your car to work. Given these are averages, it is important to note that travel times are often much worse many days of the year.

The INRIX U.S. Scorecard also takes a micro look at traffic problems all across the country — zooming in on the total hours spent in traffic, worst day of the week for commuting and average speeds for the Top 100 U.S. cities along with hundreds of other details. 

Unique patterns evolving out of U.S. traffic congestion include:

    • Worst Traffic Day: Thursday
    • Worst Week Day Morning: Tuesday 
    • Worst Commuting Hour: Friday 5-6 p.m.
    • Worst Evening Commute: Friday
    • Best Week Day for Traffic: Monday
    • Best Week Day Morning: Friday morning
    • Best Week Day Commuting Hour: Friday 6-7 a.m.
    • Best Week Day Afternoon: Monday

The Annual INRIX Traffic Scorecard is based on analysis of raw data from INRIX's own historical traffic database generated by the company's Smart Driver Network of more than 4 million vehicles traveling the roads everyday including taxis, airport shuttles, service delivery vans, long haul trucks as well as consumer vehicles and mobile devices. 

Each data report from these GPS-equipped vehicles and devices includes the speed, location and heading of a particular vehicle at a reported date and time. 

In creating the Scorecard, INRIX analyzes information for every road segment during every hour of the day to generate the most comprehensive and timely congestion analyses to date, covering the largest 100 metropolitan areas and the nation's entire highway, interstate and limited access road network.