Here's why the traffic signals seem poorly timed



Above: Photojournalist Walker Anderson and Kaci attempt to navigate some of the more frustrating signals in Seattle. Watch video below for the Mercer Mess.

SEATTLE -- We hear you. It feels like traffic- everywhere- is worse than it has ever been. And it's not just the freeways; the surface streets are just as tough, especially when it feels like the intersections are timed to make you late for wherever you are going!

Photojournalist Walker Anderson and I decided to head out through some of the more frustrating types of intersections, based on your suggestions, through downtown Seattle. And by "types" of intersections, we mean "pretty much any intersection along Mercer" and "that intersection that is right next to another intersection, but the lights are never in sync, so you go through a green light only to stick out in the middle of the intersection with a red light that comes right after it."

Which, of course, can refer to MANY intersections across all cities. But we digress.

We took our frustrations to the folks at the Seattle Department of Transportation. SDOT director Scott Kubly was kind enough to sit with us for a chat that lasted well over an hour, covering everything from our curiosity about why certain areas seemed to be timed a certain way; to what the heck is being done about some of the more crowded areas. Here are some of the highlights that we think might make everyone feel better.

First, no matter where you live, know that you don't have to sit and scream to yourself in your car as your only means of venting frustration. If a particular intersection seems to always be red in your direction, while there are zero cars coming in the other direction, it can be frustrating to just sit there and stew. So don't. I mean, yes, obey the red light- but instead of stewing, take action. Kubly tells us they do take commuter feedback seriously, and even though they can't get to every concern at once, it does get added to a list to be checked out.

How to notify SDOT of intersections that seem poorly timed or out of whack: Tweet. According to Kubly, someone at SDOT is monitoring the twitter feed 24/7, so if there is a blinking light, or a weird situation with an area, tweet: @SeattleDOT. You can also call their hotline: 206-684-ROAD.

The Mercer Mess: How are they tackling it? Starting now and continuing into the next year, the city is installing new technology along some of the busier corridors, like Mercer, Denny, and 23rd Ave. The technology, called Adaptive Signal Systems, aren't just about timing one intersection at a time. The system takes an entire area of intersections into account to try and time all signals in a way that moves traffic along the smoothest. The technology works by using sensors either in the pavement or on the signal mast arm, and monitoring the system along the entire corridor to determine a pattern that will work best. For example, if there is really light traffic in one direction, it will adapt to hold the green light green for a longer period of time in the other.

"Those adaptive signal systems actually get better and more powerful as we get more of them, and they actually are most effective in that off-peak time," Kubly says. "When the peak period is going on, there's so much traffic in every direction, you can't really adjust the signals too much. But it's in the evening, late at night when you can actually start doing that."

What about the rest of the lights through downtown? There are 300 traffic signals in the downtown Seattle area, and they're going to tackle it by breaking it into different subzones. "Right now, they're all timed based on one big downtown zone, so we're creating about a dozen small zones and we'll be re-timing all the downtown signals," Kubly says. "And in having it in different zones, we can have a little more fine-grained tweaking of the system."

What about those weird instances of one intersection right after the other, where you can't really fit more than one car up to the stopline without sticking out in the intersection behind you? This is something that is tough to tackle, because of all of the "diagonals" In other words, not all of our streets fall along a delightfully perfect grid. "Seattle has... colliding street grids," Kubly tells us. "You have a center city, and you have South Lake Union and you have Denny Triangle and Pioneer Square. There's all these different streets coming in at different angles," meaning they don't always meet in perfectly separated intersections. Bottom line: those one-right-after-the-other intersections can't be re-timed so easily when it affects so many other directions at once. Patience, in this case, is key.

But isn't it true they can change the timing of intersections from the SDOT headquarters? Why not change the timing of lights, every day, in real-time? Turns out, it's not as simple as that. As Kubly tells us, you have to remember that with so many intersections in a concentrated downtown, you can't change the timing of one signal without affecting the timing of every other intersection around it.  So you can't just re-time an intersection on a whim when you look down and see that it's crowded. That could cause a mess at the intersections around it!

It's true, though, that about 80% of the downtown signals can be changed, timing-wise, from SDOT headquarters. It just wouldn't make sense to do it one intersection at a time, off and on, throughout the commute. But it does mean they can change the timing patterns for an event, or a serious accident. For example, when the president of China visited Seattle, the folks at SDOT were able to change the timing patterns in the areas around the streets that were closed for the president to use. Another example? There are different timing patterns they switch to for sporting events like a Seahawks game.

Bottom line: Yes, SDOT knows the traffic is bad. No, they aren't sitting in their office refusing to do anything about it! With the new technology along the major corridors, plus the new efforts to re-time lights throughout the entire city, the hope is to alleviate some of our stress. "Hopefully what we get is a more resilient system," Kubly says, "and one that's a little more predictable. And I think that's the most important thing, is predictability of how long it will take to get somewhere, versus, one day it's five minutes and one day it's an hour."

Which brings us to our final point: What can we, as commuters, do to make it easier... on each otherPatience. Believe it or not, Kubly tells us one thing that does add to the intersection clogs is people "blocking the box", or getting stuck in the intersection by running a late yellow or very red light. All it takes is one person to do that, and think about how it impacts an entire line of cars who can't get around it.

And, of course, I have to add this: ALWAYS USE THE THANK YOU WAVE. If someone lets you turn in front of them in a crowded intersection, a wave will lessen quite a bit of this stress!

Click HERE to go to SDOT's website and read more about their work on some of these issues.