Seattle’s Congestion Future Is Bleak Without More Road Capacity

We can build our way out of this mess

When it comes to traffic jams, the Seattle-Tacoma area is the most congested in the Northwest, just ahead of much-smaller Portland, and ranks 12th nationwide. The area has a congestion index of 1.38, meaning that trips at rush hour take 38 percent longer than off-peak journeys. But if you think that’s bad, just wait until 2030.

Over the next 25 years, after absorbing almost 1 million more residents and even more car and truck trips, that same rush-hour trip will take 79 percent longer than a trip made at off-peak times, making Seattle’s congestion even worse than the gridlock experienced in Los Angeles today. A trip in Seattle that is supposed to take 30 minutes, will take over 52.

And by 2030, Seattle will have jumped up to the 8th worst commute in the nation.

This forecast comes from our new Reason Foundation study and assumes that all transportation projects in the region’s current 25-year plan are actually implemented. The Seattle transportation plan proposes to spend $102 billion over 25 years, including $46 billion for transit and $49 billion for highway projects.

Many motorists or taxpayers might well be asking: do you mean that we are going to spend $102 billion over the next 25 years, and our congestion will be significantly worse after all the spending? Sad to say, the answer is yes.

That’s because local transportation planners have bought the idea that we can’t build our way out of congestion, so it’s hopeless to try. In keeping with recent trends around the country they focused more on reducing driving, proposing mass transit systems and high-density housing projects intended to get people out of their cars. They know that the demand for highway travel will be greater than the supply, but instead of increasing road space in response to what people want they hope to reduce the demand instead to fit within the limited available road space.

This is the approach California tried for 20 years. In the 1980’s California stopped building freeways and poured billions of dollars into rail transit systems in Los Angeles, San Francisco, San Jose and San Diego. Unfortunately, the planners couldn’t close the door: people kept moving to California and they brought their cars with them. Transit use and carpooling today handle a smaller fraction of trips than they did 20 years ago. The result is that Los Angeles and San Francisco top the national charts in congestion. Other cities that have lately tried the California model have seen their congestion soar, as well. Seattle is one of them.

But the tide may be turning. To its credit, Seattle is among a handful of cities that have gingerly begun to investigate the costs and benefits of expanded highway capacity. And our new research suggests that adding highway capacity is the most important part of an effective effort to reduce traffic congestion.

Our study modeled the hypothetical addition of enough capacity in every U.S. metro area to eliminate the worst congestion by 2030. Seattle was one of the participating cities in that analysis. We found the Seattle region would require adding 704 lane-miles to the existing highway system over the next 25 years, on freeways, arterials, and local roadways. We estimate the cost of that as $4.8 billion in today’s dollars. That amounts to a bit under $34 per resident per year, but is less than a tenth of what Seattle plans to spend anyway. So, just by re-focusing its present spending, Seattle could actually reduce congestion if it chose to do so. That investment would save 200 million hours of delay per year that would otherwise be spent stuck in traffic, and the cost, just 96 cents per hour of delay saved — and that is 1/ 20th the minimum cost for light rail proposals.

Where would the new capacity go? While our study did not get into this level of detail, one of most likely possibilities is to add a complete network of HOT or express toll lanes to the existing freeway system. Another possibility is adding truck-only toll lanes in selected corridors, as Atlanta and Los Angeles are now planning to do. Many major thoroughfares that serve growing suburbs should also be widened to handle the traffic that we know is coming.

The Seattle region is at a crossroads in transportation planning. Pulling one way are those who favor the California model: try to get people out of their cars by diverting transportation funds away from highways and into transit and land-use densification. On the other side are harried commuters just trying to cope. In reality, there is no realistic alternative to highways for personal mobility, goods movement, and bus transit, so we need to keep growing the highway system in step with demand for vehicular travel. Cities like Atlanta and Houston – and now Seattle – are beginning to re-think their planning to focus more on congestion relief, and we applaud this trend.

The Seattle region is in competition with other cities as a place to live, do business and play. Seattle’s ace cards are its great environment and easy access to the world stage. But these will not be enough. A key factor in people and companies’ location choices is mobility: does the transportation system permit smooth and reliable commuting, goods movement and personal trips for recreation and tourism? Those metro areas that can offer such mobility will break out of the pack, ahead of those whose systems are increasingly gridlocked.

Which future do you want for Seattle?

David Hartgen is professor of transportation studies at UNC Charlotte. Robert Poole is Director of Transportation Studies at the Reason Foundation. Their new traffic congestion study is available online at Reason’s transportation research and commentary is here.