It is about that time of day when thousands of geeks hop in their cars and make the commute over the 520 floating bridge — the main artery connecting Seattle and Redmond. For those stuck in traffic — which can be particularly horrendous on days when the sun emerges after long spells of cloudy weather (like today) — the commute is one of the most dreaded parts of the day.

But here’s some news you probably don’t want to hear (or won’t believe) if you are about to get stuck in the 520 mess. An analysis by Clark Williams-Derry at the Sightline Institute finds that traffic patterns on the state route 520 bridge actually have declined in the past decade. (See chart below).

That shocked us, in part because Microsoft’s employment in the region has mushroomed during the same period Williams-Derry analyzed.

Microsoft, which is by far the biggest contributor to commuters on the 520 bridge, now employs 40,000 people in the Puget Sound region. (89,000 worldwide).

That means the company has added roughly 15,000 employees in the Seattle area alone in the past five years. Even more startling, if you look at the employment growth at Microsoft in the region since 1995, it has added a whopping 30,000 employees here.

Now, some of those workers may be telecommuting, living on the Eastside already or hopping on the Microsoft Connector bus service. But, I am guessing, a number of those workers are also driving in their cars over the floating bridge.

So, how has traffic actually declined given those employment gains?

That’s a good question, and we’ll probably need a transportation or statistics guru to help figure it out.

But Sightline’s Williams-Derry is using the analysis — along with what he says are some wild future traffic projections for the bridge from WSDOT — to shine a light on what he perceives as a wasted investment in a plan which is moving ahead to expand the 520 bridge to six lanes.

“It would be funny—if the state weren’t planning billions in new highway investments in greater Seattle, based largely on the perceived “need” to accommodate all the new traffic that the models are predicting will show up, any day now,” he writes.

Seattle Mayor Mike McGinn has continued to fight the 520 bridge project as well, and a blog post from the Mayor’s office today jumps on the numbers as well.

“Designing for thousands of cars per day that may not show up has resulted in a project with six lanes and a bigger footprint,” the Mayor’s office wrote. “A bigger footprint could cost us more money, more loss of wetland habitat, and cause bigger impacts to Seattle’s neighborhoods.”

They also point out that traffic across the bridge likely will drop once tolling begins, which is scheduled to happen this summer (but has been delayed on several occasions already).

Interestingly, Microsoft CEO Steve Ballmer spoke of the bridge project at Seattle Rotary late last month, noting that it was the type of progress the region needed in order to remain competitive.

Sightline Institute says traffic has declined on the 520 bridge in the past 15 years despite Microsoft adding 30,000 employees in the region.
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  • Kristin Eide

    Hmm…even if traffic has declined it’s still a total disaster on 520 during rush hour. It takes me 45min-1hr to commute between Redmond and the U-District each way (around 13 miles). I can’t even imagine what traffic was like 10 years ago if it was worse.

    • Jason Burt

      Yeah, I wont leave work until 7-7:30 cause it takes so long to get across the bridge. 

  • TheDavidAiken

    Clearly there is a need to have more capacity across 520, but it is crazy to see that we will still be horribly dependent on our cars and the ever increasing Gas prices.

    I’d love to have seen some effort on alternative transports – light rail etc.

    Can you imagine getting from U-District to Redmond in 11 minutes?

    • Kristin Eide

      It takes me about 15 minutes if I commute after 7:30pm (which usually ends up happening when I get swamped at work). I use to take the bus but it took me the same amount of time and I’m not the best with schedules ;). I am interested to see what traffic looks like when the tolls begin.

  • Guest

    That Seattle took over 100 years to get regular commuter train service is an embarrassment. That Seattle Microsofties still have no option to get to work except cars (traffic), buses (which go in the same traffic), or private company shuttles (seeing a trend here?) is even more embarrassing.

    Build a bridge, Seattle. Build trains. Get workers to work without sitting in traffic.

    Whether the commute is getting slower is immaterial, gentlemen. The public transport infrastructure in Seattle is insufficient for a city half our size. That commutes haven’t gone from 45 minutes up to 60 minutes is not an achievement. Build a train. Make my trip take 15 minutes whether it’s 9 AM or 10 PM.

    Build it, gentlemen. Build. Stop talking. Build.

  • Guest

    The WSDOT forecasts are crazy, but the chart is misleading. You can’t total traffic across a day and call that meaningful. What is commute time like? I would bet commute time has gotten worse while non-commute time has gotten significantly better.

    Non-commute times might be better both because people have fewer reasons to do the drive and they are discouraged from doing so because of heavy traffic. Commuters don’t have the same choice.

  • Kelly

    The Connector bus service and Sound Transit have made a huge difference. The Connector is usually full on most days… and in the afternoon, I’ve had to wait through multiple SR545 buses since they are full.

    Still, the 520 commute is a nightmare… like it was 10 years ago… and 15 years ago… and 20 years ago :(

  • Anonymous

    Don’t forget that the added lanes will be limited to carpools, vanpools and buses, so it’s not as if the road is being expanded for solo drivers. The expansion will allow buses to get across the bridge in much more timely fashion, thus giving a preference to more environmentally preferable modes of transportation. Right now buses get stuck in traffic.

  • Anonymous

    Perhaps the “decline” is due to those of us who are paranoid about getting stuck on in when there’s an earthquake and drowning in Lake Washington after 520 whiplashes apart.

    Or perhaps that’s my reason for vowing never to have to do that commute.

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