Posted at 12:35 p.m. PST; Tuesday, November 23, 1999
Copyright 1999 The Seattle Times Company
Worst bottlenecks
The nation's top 18 highway bottlenecks
1. Los Angeles, Interstate 405 at I-10
2. Houston, U.S. 59 at I-610
3. Seattle, I-5 at I-90
4. Boston, I-93 Central Artery downtown at U.S. 1 known as the "Big Dig"
5. Washington, D.C./Maryland, I-495 at I-270
6. Washington, D.C./Virginia, I-95 at I-495 and I-395 known as the "Mixing Bowl"
7. Los Angeles, U.S. 101 Ventura Freeway at I-405
8. Los Angeles, State Route 55 Newport Freeway at State Route 22
9. Los Angeles, I-10 Santa Monica Freeway at I-5
10. Albuquerque, I-40 at I-25
11. Atlanta, I-285 at I-85 in De Kalb County
12. Atlanta, I-75 at I-85
13. Chicago, I-290 at the junction of I-88 and I-294 called the "Hillside Strangler"
14. Denver, I-25 at I-225
15. Houston, I-610 at I-10
16. Washington, D.C./Virginia, I-66 at I-495
17. Washington, D.C./Maryland, I-95 and I-495 at the U.S. 1 to I-95 North junction
18. Atlanta, I-285 at I-75 American Highway Users Alliance
  Interstate 5 at I-90 named
third worst bottleneck in U.S in highway study
by Seattle Times staff and The Associated Press
Slowdowns at Interstate 5 and I-90 amount to the nation's third-worst traffic bottleneck, according to a study released today.
In the latest dubious honor for Seattle's traffic system, the interchange was singled out by the American Highway Users Alliance, along with 17 other snarls, including Chicago's "Hillside Strangler," the "Mixing Bowl" in the Washington, D.C., area and Boston's "Big Dig."
Just last week, a separate report said the Seattle-Everett area had the third-worst traffic congestion in the nation, forcing drivers to spend an average of 69 hours a year stuck behind the wheel.
Today's study focuses more narrowly on bottlenecks, which is sure to spark debate among commuters in the Seattle over whether peak traffic on I-5 and I-90 is actually worse than other interchanges that become heavily congested during rush hour, such at I-90 and I-405 in Bellevue.
The study was based on traffic volume and average delays during peak periods in the morning and afternoon, said Rich Margiotta, with the Boston consulting firm Cambridge Systematics, which conducted the study for the Washington, D.C.-based alliance.
That means a freeway with eight lanes is going to be deemed more congested over one with four, even if traffic seems to move more slowly on the latter, Margiotta said.
"The one with higher volume is going to win," he said, conceding that the "blob" at I-405 and I-90 is often larger.
"It's a combination of high volume and congestion," Margiotta said, adding that the traffic volumes pumped through I-5 at I-90 are "just tremendous compared to other areas."
No bridges or toll roads were included in the study.
Analysts used data provided by the Washington state Department of Transportation to the federal government, Margiotta said. Delays were measured by comparing speed limits against the true speed of traffic.
Another bottleneck that scored high was at I-405 and State Route 522 in the Bothell area, he said.
"You've just got congestion in a lot of different areas," Margiotta said.
In addition to identifying bottlenecks in nine metropolitan areas, today's study found that fixing the most serious congested areas nationwide would save lives, reduce pollution and shorten delays.
Spending more on synchronized traffic lights, using computerized systems to route traffic around congested areas, and using reversible commuter lanes and movable barriers during peak travel times will help, the alliance said. But in some instances, America's overstressed road system needs additional capacity at key points, it said.
"Freeing these bottlenecks is a critical starting point for curing the gridlock on our roadways," said William Fay, president of the alliance, which represents motorists, truckers, insurance companies, oil refiners and others with an interest in safe, uncongested roadways.
The study estimates that improving 167 bottlenecks nationwide would, during the next 20 years, prevent 287,200 crashes, reduce smog-causing emissions and cut delays by an average of 19 minutes a trip - nearly 40 minutes a day for commuters who must negotiate a bottleneck to and from work.
Steve Hayes, a spokesman for the American Automobile Association, said the study focuses attention on expanding the capacity of America's road system.
"The number of automobiles and trucks on the highways has grown dramatically in the past 30 years, but the miles of new road has only increased very, very slightly," Hayes said. "They certainly have a point that attention needs to be paid, and especially to these bottlenecks."
Deron Lovaas, representative for the Sierra Club's Challenge to Sprawl campaign, said easing congested bottlenecks makes sense in the short term but not in the long term. Money needs to be invested in alternative transit, such as buses or commuter trains, he said.
"Building new lanes for existing roads or building new roads to deal with road congestion is like buying a bigger pair of pants to deal with a weight problem," Lovaas said. "New roads act as magnets for cars. People see this uncongested road and they opt out of taking the train, riding the bus and walking. You end up with more people driving more miles."
Copyright 1999 The Seattle Times Company