Complaining about traffic is like complaining about rain — it’s part of living in the Puget Sound region. But why is traffic so bad? We went looking for answers.

Behind the Wheels

Photo by Rachel Coward

Few things are more frustrating than sitting in traffic.

Whether you are in your car and inching along Interstate 405 through downtown Bellevue, packed onto a Metro bus and stopped halfway across the State Route 520 floating bridge, or idling on your motorcycle somewhere in the darkened interior of the Mercer Island tunnel, the observation that traffic in our region has gotten worse isn’t entirely anecdotal.

“What we have seen in the last five years in our region is that on our freeway system, congestion has doubled,” said Josh Brown, executive director of the Puget Sound Regional Council, the area’s leading organization that studies transportation, economic development, and growth management. “Think about your daily commute. Where you spent five minutes five years ago not driving the speed limit, today you are spending 10 minutes.”

It’s not just major highways that are feeling the pinch. Traffic volumes on surface streets are increasing, too, and most cities bemoan the rise in pass-through traffic as commuters look for shortcuts through cities and towns. But traffic flow is like water flow: Once you find an easier route from Point A to Point B, others will figure it out, too.

The State of Washington and local transportation agencies are working on a number of projects that aim to reduce traffic congestion. But will they be enough to address a growing population and strengthening economy that seem to be outpacing our ability to build more roads, add more buses, and introduce new transportation options? Will local voters see more ballot measures raising property taxes in order to keep up with the flow of traffic?

We asked some of the top transportation planners, strategists, and analysts in the area to share their knowledge on the state of Eastside traffic. What we found were fairly simple and obvious reasons for a problem that engenders so much angst. Yes, our roads are more jammed, but that’s because there are more people due to a strong economy that has produced more jobs. What’s more nuanced is that these people are driving on roads and using a public transit system that some say should have been built decades ago. Factor in our region’s landscaped obstacle course of waterways and mountains, and you have a formula for terrible traffic.

Map by Alex Schloer and Mike Forbush

Map by Alex Schloer and Mike Forbush


Josh Brown: Congestion in our region has increased dramatically at the same time our regional economy has added 270,000 jobs. These are linked. The strength of the regional economy has direct impacts on our transportation system. Most people work traditional schedules and need to get to work at a certain time. We benefit from a strong regional economy, but our transportation network — both transit and roads — becomes burdened with this new economic activity. With 4 million people in our region and another 1 million new residents by 2040, we must continue to provide transportation solutions for our growing region.

Bart Phillips: King County grew by 52,300 people between 2015 and 2016. That is a growth rate of 2.5 percent. Redmond’s population has grown by 34 percent over 2000 levels, 69 percent over 1990 levels, and Redmond’s job growth tends to hover around 1.7 percent a year. But population is not the only factor. As jobs are being created in Redmond and the Eastside, more people are commuting from farther distances to get into the area each day, compounding the problem and lengthening commute time and congestion. Barring a recession, auto traffic will never decrease.

James Henderson: In some ways, traffic is an economic indicator. If we see a lot of traffic, that means our economy is doing fairly well. In some ways, it’s a positive thing. It may not be a positive thing when you are sitting in it. But it is a very good leading indicator of how your city is doing.


Brown: There are a lot of examples of transportation projects that we wish were completed 10, 20, or 30-plus years ago. Moving forward with a regional rail network in the 1970s is one such example. So is the completion of improvements to Interstate 405.

Many improvements on the northern half of 405, from Bellevue to Lynnwood, are complete. Funding for the southern half, from Bellevue to Renton, was only recently secured in 2015, as part of the Connecting Washington Package. It will take nearly a decade for this corridor to be completed. These projects highlight the challenge faced when we get behind on transportation investments needed to support a growing region.

We won’t be able to meet the needs of our growing region just by adding lanes to freeways. One additional freeway lane can move approximately 2,000 cars per hour. That’s why expanding transit is so vital to our region. It allows us to get people to key job centers during peak times, adding capacity when and where we need it.

Dan Stroh: Clearly, the region was late to the high-capacity transit table. There’s no question about it. There was a series of failed measures that didn’t go through. The story is that other areas of the country basically ended up with the federal investment dollars that would have gone to Seattle during the 1970s. We were late to get it, and we are playing catch-up on high-capacity transit now.

Phillips: Growth on (our region’s) scale means that transportation facilities, like expanded roads and mass transit lines, cannot be built fast enough to provide a consistent level of service through time.

Dave Berg: I’ve worked at the City of Bellevue since 2000. Some of our first projects were widening our two-lane roads to four-lane roads. Those two-lane roads were packed, they were backed up every day. Now those four-lane roads are packed, and they are backed up every day. Those kinds of improvements buy you some time, but they quickly fill in between growth and the latent demand that is out there — people who want to travel, but they don’t because it’s too congested. You widen lanes, there’s growth over a couple of years, and pretty soon you are back to where you started.

We are playing catch-up. Bellevue is the second-largest employment center in King County, and we still won’t have a true high-capacity transit system until 2023. You don’t build freeway capacity to reduce traffic volume. In a fast-growing region like the Puget Sound region, it is really hard to keep up. A lot of the investments to facilitate movement in and out of regional employment centers have been instrumental in keeping traffic moving. But clearly there is a lot more that could be done.

Brown: Topography is an issue in the Puget Sound. If our region were like Phoenix, relatively flat, few water bodies, and limited critical areas, it would be a lot cheaper and easier to plan for transportation. But we all know that one of the things that makes our region special is the natural beauty — from Puget Sound and Lake Washington to the Cascades. We benefit so much from those natural assets that make our quality of life great, but the trade-off is the challenge with ensuring we sustain a transportation system that meets the needs of a growing region.

Berg: There have been proposals for building a third bridge across Lake Washington connecting the University District northern area to Kirkland. But when you start thinking about the cost to do those kinds of infrastructure improvements, they are astronomical. This isn’t Phoenix, where you’ve got miles and miles of flat land. Bellevue, sandwiched between Lake Washington and Lake Sammamish, really means we have just a few north/south main routes, with Interstate 405 being the main route. There are not a lot of options, so the network is really constrained by the area’s topographical challenges.

Phillips: State Route 520, Interstate 90, and Interstate 405 are the only major highways running through the Eastside, and the only other options for commuters and travelers are surface roads. Furthermore, growth management as practiced by municipalities in the Puget Sound area means that for the most part, Eastside cities cannot grow outward — only upward.

Graphics by Mike Forbush; Source: Puget sound Regional Council

Graphics by Mike Forbush; Source: Puget sound Regional Council


Stroh: Dealing with traffic and transportation is one of these things where you’ve got to have a big toolbox, and you’ve got to throw it all at it. That means continuing to deal with congestion and roadway improvements, continuing to lobby the state for the improvements needed on the state facilities, continuing to work with Metro and Sound Transit to get the right transit services, continuing to make the right bike improvements, continuing to get the right land-use mix, and continuing to work with employers on the Commute Trip Reduction program to encourage their employees to find alternative ways to commute. There’s no one kind of magic.

We know that if you can get the right mix of land use, it has a significant impact on travel behavior. We are not going to get rid of cars, but we can affect some of that by the land-use transportation mix in an area. The classic would be a city-center kind of environment, where you have a density that is adequate to support a lot of things happening together. In the same block it’s easy to walk to get coffee or buy a jug of milk or whatever, as opposed to suburbia, where you basically have to get into your car and drive three miles to get a half-gallon of milk. If there’s more of this, future growth is going to work much better than past growth has worked.

Berg: The City of Bellevue is very anxious to see light rail come to the Eastside. It will provide that convenient, reliable travel option — it’s another one of those tools in the tool kit. For those folks who are able to use transit, and light rail in particular, they are going to have a very quick and easy ride in the region.

A year ago, we implemented the state-of-the-art Smart Signal System, which adapts to traffic conditions on a second-by-second basis to more effectively and efficiently run our signals and get more cars through our roadway network. On average, we have seen about a 10 percent increase in throughput for an investment of about $5.5 million. As an example, if we were getting 1,000 cars through an intersection before we implemented the system, now we are getting 1,100 cars through that same intersection. Another way of saying that means if you’ve got 10 lanes of traffic today, a 10 percent increase in throughput is the equivalent of getting an additional full lane of traffic for a whole other bunch of cars. We implemented the system first in downtown, then Factoria, and now it’s fully implemented citywide.

Brown: We have the fastest-growing transit ridership out of any metropolitan region in the country. Our transit ridership is growing at twice the rate that our population is growing. As more people are drawn to our region’s strong economy and quality of life, we are experiencing an upsurge of commuters relying on transit to get to work, especially in our most congested job centers.

The IT sector is responsible for much of the direct and indirect increase in our region’s jobs. These IT jobs are centered in two places in our region — Seattle and the Eastside. One of the things that will transform our region soon will be linking all our major IT assets together with reliable, fast light rail service. By 2023, light rail will connect the Microsoft campus, the Spring District (including the Global Innovation Exchange), downtown Bellevue, downtown Seattle, and the University of Washington. Connecting our region’s major IT assets, from major job centers to educational and research hubs, with high-capacity transit will be a competitive advantage for our region. Many of the peer regions we are competing against can’t claim the same regional connectivity.

Henderson: We conducted a survey (of employers) in 2015, and we will do another one this year, and basically traffic, congestion, and those types of things were the top concerns. What we are seeing now is because of light rail coming to the Eastside — particularly the downtown, Spring District, and Bel-Red areas — a lot of companies want to be in those areas, which have higher densities, a mix of both commercial and residential properties, and other amenities that employees and employers really like.

Phillips: We need to continue to fund transit service and transit expansions, and make sure cycling and walking are safe, viable options. The Eastside is not Manhattan, or even Central Seattle, and the majority of Eastsiders will be making most of their trips by car well into the foreseeable future. At the same time, every little bit helps. Even if you are only able to carpool, vanpool, or take a bus to a destination a few times a week or month, or only hop on a bike when the weather suits you, that can be enough.

Graphics by Mike Forbush; Washington State Department of Transportation

Graphics by Mike Forbush; Washington State Department of Transportation