In response to my blog supporting a rebuild of the Alaskan Way Viaduct, Cary Moon of the People's Waterfront Coalition writes:
Traffic is a strangely behavioral science, and urban congestion is really really complex. Before you rush to the conclusion that the solution we advocate at the People's Waterfront Coalition will cause a permanent traffic jam, consider these points.
The "reducing capacity will cause gridlock" threat has been around a long time, so some engineers in the UK decided to look into it more thoroughly. They found that of 60 cases of capacity reduction they studied in Europe, the UK, and North America, the expected chaos and gridlock never once materialized. They also found that an average of 25% (and up to 60%) of the trips that had used that facility stopped happening when it was removed. With advance notice and alternative routes, people are a lot more flexible than highway departments think they are.
There is widely accepted evidence that the existence of a transpo facility can cause trips to happen that might not have happened if it weren't there. The inverse may well be true as well.
Lots of smart transportation planners suggest that many market and demographic trends point to a future society that drives less. This report recommends that it may be better to anticipate these conditions, and start investing in less car-dependent transportation systems now.
Our proposal suggests fixes elsewhere in the system to accommodate most of the viaduct trips. Some trips move to improved arterials, some move to improved I-5 express lanes, some move to transit (improved, and new) and some stop happening. Freight trips are accomodated with freight only lanes on important freight routes, and perhaps special accessto the express lanes on I-5. It is bold, and admittedly people will chafe at such a big change all at once, but it's not that radical. All of these elements have been tested and proven effective in other cities. This solution was developed in collaboration with the former lead transportation planner from PSRC, who understands Seattle mobility at a deep level.
This decision about the viaduct shouldn't be made in a vacuum, as if preserving the convenience of existing car trips were the only goal, and came without any costs or lost opportunities. Our civic leaders want to make downtown dense and family-friendly, which will require great parks and public amenities. Our Mayor has pledged to reduce our greenhouse gases to below 1990 levels -- which entails aggressively reducing production of emissions, and probably car use. We've recently learned that car emissions are the #1 problem for the devastated marine ecology of Elliott Bay. Gas prices are expected to keep rising, and people will eventually be searching for alternatives to driving. The number one culprit in the current public health crisis (obesity, childhood asthma, etc.) is our drive-everywhere culture.
Before we invest more money than we've ever spent on anything to retain a 1.5 mile stretch of highway, we should consider a cheaper, more sustainable alternative. Especially since we may not even have that money, and many local leaders are of the "over my dead body" opinion of the aerial alternative.
Cary Moon
People's Waterfront Coalition
Respond about the Viaduct.