Traffic

Traffic Q&A: What does ‘severe’ mean in those wind warnings on the Tacoma Narrows bridges?

Washington State Department of Transportation workers use windsocks, like the one at upper right, to decide whether to issue “severe side wind” warnings on the Tacoma Narrows bridges.
Washington State Department of Transportation workers use windsocks, like the one at upper right, to decide whether to issue “severe side wind” warnings on the Tacoma Narrows bridges. Staff writer

Q: I’d like to know what the Department of Transportation considers “severe” winds. Many times, the electronic reader boards on either side of the Narrows Bridge will say, “SEVERE SIDE WINDS ON BRIDGE.” What one encounters, if anything, are a few gusts easily controlled with a little flick of the wrist applied to the steering wheel. – David B., Rosedale

A: David, dear readers, has strong feelings about this.

His missive to Traffic Q&A headquarters also included this verbiage:

“One imagines semi-trailers tipping over, cars being blown into the guard rails, pedestrians unable to remain standing. This type of crying wolf (not to mention numerous signs urging, “MOTORCYCLES USE EXTREME CAUTION”) makes me wonder what source of this rampant alarmist signage is. Thanks for any enlightenment you can provide.”

Now, we are not apologists for the state Transportation Department.

We have cursed that agency on more than one occasion while crawling through what seems to be the never-ending construction on Interstate 5 through Tacoma, especially on Friday evenings when we are eager to get home and salve our battered souls with a nice cold adult beverage.

But we tend to give the department the benefit of the doubt when it comes to wind and the Tacoma Narrows bridges, as the agency has a well-earned sensitivity to that issue because some strongish breezes a few years back BLEW DOWN THE ORIGINAL BRIDGE!

Still, a question is a question, so we put David’s to Claudia Bingham Baker, spokeswoman for the Transportation Department’s Olympic Region, which includes Tacoma.

Bingham Baker provided the following answers:

“Staff at our Traffic Management Center monitor the wind blowing across the Tacoma Narrows bridge decks in three ways, all low-tech and all effective:

“1) They monitor wind socks on the bridges and issue warnings when the socks are fully extended;

2) They monitor how well motorists, and large trucks in particular, are staying in their lanes;

3) They use input from (the Washington State Patrol) and other partners to help gauge when winds are getting unruly.”

The department does have some sophisticated meteorological equipment on the spans, but Bingham Baker said it has limitations.

“That instrumentation is on the tops of the towers, and wind speeds at that elevation are often different than wind speeds at the roadway deck level,” she said.

Bingham Baker went on:

“We know the word ‘severe’ is not a term used on the Beaufort Wind Scale. We use it because it matches static signs approaching the bridge.”

She then defended her agency’s honor:

“Our goal is not to be alarmist, as your reader suggested, but to warn drivers of all types of vehicles when they need to be aware of wind conditions, so they can adjust their driving accordingly.

“We care more about the safety of drivers crossing the bridges than we do about the nautical correctness of the term or the frequency with which the wind conditions justify the warning.

“After all, it is not unknown for semis to be blown over while trying to cross those bridges.”

We don’t think they’re blowing hot air, here, David. But maybe that’s just us.

Adam Lynn: 253-597-8644, @TNTAdam

  Comments