Politics & Government

South Sound traffic congestion accelerates

Friday evening rush-hour traffic backs up last month on Interstate 5 through Olympia.
Friday evening rush-hour traffic backs up last month on Interstate 5 through Olympia. Staff file, 2014

It’s a long 10 miles — one of the longest on Washington’s highways.

Drivers braving Interstate 5 during evening rush hour last year needed to set aside 42 minutes to be reliably sure of reaching Tacoma from Federal Way.

Another epic crawl: the 17 miles from Lakewood to Lacey. For that one, drivers had to allow themselves 49 minutes.

An annual report being released Monday (Oct. 26) by the Washington state Department of Transportation identifies choke points statewide and paints a picture of increasing congestion in the South Sound.

“That window of time for rush hour in morning and afternoon is growing,” WSDOT spokesman Lars Erickson said.

$808 millionCost of delay on state highways to drivers and businesses in 2014. That’s about $116 per Washingtonian.

The slow recovery from the Great Recession left people driving less, so gridlock fell, too. Statewide, congestion is rising but remained lower last year than before the recession — about 8 percent below the previous peak.

But on three major highways in King and Snohomish counties — I-5, Interstate 405 and Interstate 90 — delays have bounced back and surpassed prerecession peaks.

The state has only recently started keeping similar records farther south. But for the handful of years of data available, delay on state highways in Pierce and Thurston counties and on I-5 through those counties has hit high points.

The time drivers collectively sat in delayed traffic in the South Sound dipped in 2012, but in the two years since, it has doubled.

99 percentIncrease, 2012-2014, in collective time spent in congestion on I-5 in the South Sound.

105 percentIncrease, 2012-2014, in collective time spent in congestion on all state highways in the South Sound.

4.6 percentIncrease, 2012-2014, in collective time spent in traffic delay on all state highways statewide.

That doesn’t mean commutes are taking twice as long. What it does mean: “The time that the average driver in Pierce and Thurston county is driving 50 mph or less has increased,” Erickson said.

WORST CHOKE POINTS

To gauge congestion across commutes of different lengths, WSDOT uses a measurement that compares how long it takes to drive a stretch of highway with how long it would take at the most efficient speeds.

By that measure, Washington’s most congested 2014 commute was the one that confronted morning drivers on the last 2 miles of I-5 in Vancouver before crossing the Columbia River into Oregon.

The second-worst commute last year was the 10 miles from Federal Way to Tacoma. On average, it took a lone driver 32 minutes to make the trip, up nine minutes and 39 percent from two years earlier.

5 hours and 35 minutesThe amount of time on 2014 afternoons and evenings that speeds from Federal Way to Tacoma dropped below 45 mph — an increase of one hour and 25 minutes from 2012.

Several factors could be involved in worsening traffic, such as a strong job market in King County and less expensive housing in Pierce County that encourages more people to live farther from their jobs.

Why a bottleneck in Fife? One factor could be carpool lanes that now extend south into Pierce County, where they end. Another could be road work starting near the Tacoma Dome and finishing up in the Nalley Valley. The ongoing I-5 work will let drivers use carpool lanes from Everett to Gig Harbor one day, but that day is years away.

Delays on the Federal Way-to-Tacoma segment helped increase greenhouse-gas emissions by 5 percent on that stretch, according to WSDOT.

Another way to measure the worst choke points is by how much time drivers collectively spend in congestion at those points. Spots in King County top the list in that category because there are more drivers.

The most congested spots in Pierce and Thurston counties? Counting it that way, the Fife curve ranks second behind Joint Base Lewis-McChord, where drivers collectively spend an average of 276 hours a day in congestion.

Lawmakers increased the gas tax this year to pay for highway projects including improvements to I-5 along the military base, work that is sure to worsen delays in the short term but promises to eventually ease that bottleneck.

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