Ranking the nation’s most congested highway corridors

Truckers will have a better idea of exactly where to expect traffic delays, as well as some help in planning for them, thanks to a report released by the Texas Transportation Institute (TTI), a Texas A&M University System agency, that researchers said is the first nationwide effort to identify the nation’s most congested corridors to quantify travel reliability problems.

The 2011 Congested Corridors Report looked at specific stretches of highway responsible for significant traffic congestion at different times and different days. Researchers noted that the corridors included in the report were identified by the data itself.

“Until now, we’ve been able to measure average congestion levels,” noted TTI Research Engineer Bill Eisele, “but congestion isn’t an ‘average’ problem. Commuters and truckers are understandably frustrated when they can’t count on a predictable trip time from day to day.”

INRIX, a leading provider of traffic data and analytics, originated the corridor approach, using 10 hours of congestion per week to define a starting point for a congested corridor. To be considered a “corridor,” according to the INRIX standard adopted for this report, congestion should impact a freeway segment at least 3 miles long.

Eisele credited the data and corridor listing provided by INRIX with making it possible for researchers to quantify traffic congestion, and the even more frustrating variation in congestion from day to day in major urban areas across the country.

The report describes congestion problems in 328 seriously congested corridors over a variety of times — all day, morning and evening peaks, midday, and weekends. Much of our national congestion problem exists in a relatively small amount of our freeway system, researchers point out.

Not only were these roads found to have more stop-and-go traffic than others, they were also much less predictable — “so, not only does it take longer, commuters and truckers have a difficult time knowing how much longer it will take each time they make the same trip” said co-author David Schrank.

Among the report’s key findings:

• The 328 corridors, while accounting for only 6% of the nation’s total freeway lane-miles and 10% of the traffic, account for 36% of the country’s urban freeway congestion;
• The 328 corridors account for 8% of the national truck traffic and 33% of urban freeway truck delay;
• Travel time reliability is more of a problem around bridges, tunnels and toll facilities, both because there are few alternate routes available in such circumstances and because a small incident can have a huge effect on corridor travel times;
• When travel time variability increases, your trip becomes less predictable. Every occurrence of an unpredicted travel disruption creates slower speeds than normal and contributes to an increase in our reliability measures.

The report includes tables with various congestion measures including one with the amount of daily truck travel on each corridor.

Key findings of in regards to truck congestion include:

• The northbound Harbor Freeway in Los Angeles between I-10 and Stadium Way has the most truck delay per mile at just under 100,000 hours per mile in 2010.
• The US-101 southbound in Los Angeles between Ventura Boulevard and Vignes Street ranked first for wasted diesel by trucks with over 1.5 million gallons.
• The Riverside Freeway (CA-91) eastbound in Los Angeles between CA-55 and McKinley Street ranked number one for truck congestion cost at over $67 million in 2010.
• The Los Angeles area had 16 corridors ranked in the top 40 for truck delay. New York had the second most corridors ranked for truck delay with 9, while Chicago was third with 4 corridors. Each of these regions has significant truck traffic due to large populations and proximity to ports and intermodal facilities.
• Significant truck congestion was not limited to corridors in the largest metropolitan regions. For example, Baton Rouge with eastbound I-12 and Austin with both northbound and southbound I-35 were included in the top 40 corridors.

The top 20 ranked truck congestion corridors are:

1. Los Angeles Harbor Fwy/CA-110 from I-10/Santa Monica Fwy to Stadium Way/Exit 24C
2. Los Angeles Harbor Fwy/I-110 from 111th Pl. to I-110/I-10/Santa Monica Fwy
3. Los Angeles San Diego Fwy/I-405 from I-105/Imperial Hwy. to Getty Center Dr.
4. New York Van Wyck Expy/I-678 from Belt Pkwy/Exit 1 to Main St/Exit
5. New York I-278 from (Gowanus Expy/Brooklyn Queens) 92nd St/Exit 17 to Apollo St./Meeker Ave./Exit
6. Los Angeles San Gabriel River Fwy/I-605 from Beverly Blvd. to Florence Ave.
7. Los Angeles Riverside Fwy/CA-91 from CA-55/Costa Mesa Fwy. to Mckinley St .
8. New York I-278 from (Brooklyn Queens/Gowanus Expy)
   NY-25A/Northern Blvd/Exit 41 to NY-27/Prospect Expy/Exit
9. Los Angeles Santa Monica Fwy/I-10 from CA-1/Lincoln Blvd/Exit 1B to Alameda St.
10. Los Angeles Santa Monica Fwy/I-10 from I-5/Golden State Fwy. to National Blvd.
11. Chicago Stevenson Expy/I-55 from State St/Exit 293C to Pulaski Rd./Exit
12. Chicago Eisenhower Expy/I-290 from S. Ashland Ave./Exit 28B to 9th Ave./Exit 19B
13. New York Van Wyck Expy/I-678 from Horace Harding Expy/Exit 12A to Linden Blvd./Exit
14. Pittsburgh Penn Lincoln Pkwy/I-376 from Lydia St/Exit 2 to US-19 TK RT/PA-51/Exit 5
15. Austin I-35 from US-183/Exit 239-240 to Woodland Ave.
16. Baton Rouge I-12 from Essen Ln. to O'Neal Ln.
17. Austin I-35 from Shelby Ln/St Elmo Rd/Exit 230 to Martin Luther King Blvd/19th St/Exit 235
18. Los Angeles I-110 from W. Vernon Ave. to 51st St.
19. Chicago Eisenhower Expy/I-290 from IL-72/Higgins Rd/Exit 1 to Austin Blvd/Exit 23A
20. Chicago I-90/I-94 (Kennedy/Dan Ryan Expys) from I-294/Tri State Tollway to Ruble St/Exit 52B

The top 20 corridors from 2010 are ranked by annual delay per mile. Also shown are the annual gallons of wasted fuel and the annual congestion cost associated with the delay and fuel. Key findings include:

• The highest ranked corridor for delay per mile is the Harbor Freeway (northbound) in Los Angeles from I-10 to Stadium Way. While this corridor ranks first in delay per mile, it ranks 27th in total congestion cost because it is one of the shorter corridors in the study. This corridor has about 1.4 million hours of delay per mile.
• 7 of the 10 most congested corridors in the U.S. are found in the Los Angeles region.
• The top 21 corridors in this list had at least a half million hours of delay per mile in 2010.
• 284 corridors contained at least 100,000 hours of delay per mile in 2010.
• The most wasted fuel and highest congestion cost occurred on US 101 southbound in Los Angeles between Ventura Boulevard and Vignes Street. This is a long corridor (approximately 27 miles) so it is not surprising that it would rank near the top of the magnitude measures in the table.

Top 20 most congested corridors overall:

1. Los Angeles Harbor Fwy/CA-110 from I-10/Santa Monica Fwy to Stadium Way/Exit 24C
2. Los Angeles Harbor Fwy/I-110 from 111th Pl. to I-110/I-10/Santa Monica Fwy
3. Los Angeles San Diego Fwy/I-405 from I-105/Imperial Hwy. to Getty Center Dr.
4. New York Van Wyck Expy/I-678 from Belt Pkwy./Exit 1 to Main St./Exit 8
5. Los Angeles San Gabriel River Fwy/I-605 from Beverly Blvd. to Florence Ave.
6. Los Angeles Santa Monica Fwy/I-10 from CA-1/Lincoln Blvd./Exit 1B to Alameda St.
7. Los Angeles Santa Monica Fwy/I-10 from I-5/Golden State Fwy. to National Blvd.
8. San Francisco I-80 from (James Lick Fwy/Bay Brdg) US-101 to Treasure Island Rd.
9. San Francisco Grove Shafter Fwy/CA-24 from Saint Stephens Dr. to Caldecott Tunnel
10. Los Angeles I-110 from W Vernon Ave. to 51st St.
11. New York I-278 (Gowanus Expy/Brooklyn Queens) from 92nd St./Exit 17 to Apollo St./Meeker Ave./Exit 34
12. Los Angeles Riverside Fwy/CA-91 from CA-55/Costa Mesa Fwy. to Mckinley St.
13. New York I-278 (Brooklyn Queens/Gowanus Expy) from NY-25A/Northern Blvd/Exit 41 to NY-27/Prospect Expy/Exit 24
14. Austin I-35 from US-183/Exit 239-240 to Woodland Ave.
15. San Francisco Eastshore Fwy/I-80 EB/I-580 from Cypress St. to University Ave.
16. Austin I-35 from Shelby Ln/St Elmo Rd/Exit 230 to Martin Luther King Blvd/19th St/Exit 235
17. Los Angeles CA-110 (Pasadena/Harbor Fwys) from Avenue 60 to Olympic Blvd/9th St.
18. Los Angeles I-5 (Santa Ana/Golden St. Fwys) from East Ceasar Chavez Ave. to Valley View Ave.
19. New York Van Wyck Expy/I-678 from Horace Harding Expy/Exit 12A to Linden Blvd/Exit 3
20. San Francisco Eastshore Fwy/I-80 /I-580 from Cutting Blvd. to Bay Bridge Toll Plaza

The report also includes charts that break down seriously congested corridors over a variety of times — all day, morning and evening peaks, midday, and weekends.

As the first national look at travel time reliability, researchers believe that the report can be useful in determining where transportation system improvements will have the greatest impact.

The best approach is to consider all the congestion solutions, researchers said, including traditional road building and new or expanded transit facilities, traffic management strategies such as aggressive crash removal and demand management strategies like improving commuter information and employer-based ideas such as telecommuting and flexible work hours.

The researchers stress that there is no single best way to fix the problem. The best solutions, they say, will come from efforts that have meaningful involvement from everyone concerned — agencies, businesses and travelers.

“If cities and states make the right investments in our most congested highway corridors, the return on those investments will be substantial,” says study author Tim Lomax. “Not only will we see more reliable trips for travelers and trucks, but we can also expect to see greater productivity and more jobs.”