So Seattle’s economy is hot and people are moving in as fast as they can. The traffic is going from bad to worse, but we also have money, and we would like to use that to make things better. One important question is what can our money buy. Even for a rich city, funds are limited, and we want to get the most for our money. And even with plenty of cash, right of way (ROW) is limited, so we need to prioritize the best use of the our limited space. These next two articles are a brief overview of the pluses and minuses of some of the exciting technology we have at our disposal. This article I’ll focus on personal transportation options. Next article I’ll discuss mass transit.

Freeways are relatively cheap where land is plentiful and people are few. When a freeway is freeflowing, speeds are good and you have a car where you get off, so there are no issues with mobility to and from the freeway. The two problems with freeway are one, they are spatially large, and two, they don’t really work with high traffic volumes. An example of a city which has taken freeways and roads to their limit is LA. The city is mostly flat, spacious, and implemented extensive wide freeways early in it’s development. Despite having great wide ROW and many well built freeways, LA has the worst congestion in the US.[2][3] Freeways are a great tool, but they can’t scale to handle traffic of large or dense cities.

Freeway in Puget Sound is probably not a good option going forward. The regions densest part, Downtown Seattle, is on a geographic pinch point. Hills, large bodies of water, and thin existing ROW make investing in more freeway in costly and of limited benefit. An example of a freeway style investment is the Alaskan way viaduct replacement. Seattle is trying to build a tunnel from SoDo to South Lake Union. It will be two miles, have two lanes in each direction, and was initially estimated to carry 57k vehicles (with tolls).[page442] The initial cost estimates of this relatively small section of freeway was two billion dollars[5]. It now looks like the tunnel will be significantly over budget.[4] With the size of the Puget Sound and it’s growing density, even a proper freeway system would be be congested. With our constrained freeway system and large costs for even moderate expansions, we should be judicious about further investments.

Another thing to consider with freeway expansions is the affect it will have on streets and roads. Freeways are fed by the streets and roads. Seattle has limited street capacity. To give an extreme example of our roads inability to serve our current freeways, Mercer. It was recently redone for $190 million.[6] Despite it being ten lanes wide with three through lanes in each direction, the one and only time I drove the one mile from the far side of Seattle center to I5, it took me 45 minutes. With no way of expanding the capacity of the majority of Seattle’s streets, freeway expansion can do little.

Now lets briefly talk about that contentious little vehicle, the bicycle. From an infrastructure perspective, bikes have a lot of advantages. They’re small, light on roads, and take minimal space to park. The problem is building bicycle infrastructure which is safe and gets use is tricky. Sometimes cheap minor changes become well used bicycle facilities. When Dexter was rebuilt in 2011 for $2.8 million, they used bike friendly design, including $250 thousand for bus islands. By 2013 it’s usage at peak was 300 bike per hour.[7] Contrast that with the protected bike lanes on Capitol hill. These lanes where installed at the same time as the new street car track so cyclist wouldn’t get caught in the tracks. The cost of the lane was included in the cost of the streetcar. The bicycle infrastructure is extensive, including special signalization for the bikes and full curb or parking separating bikes from motor vehicle traffic. There is a large amount of destinations along the route.[8]  In spite of the prime location and best practice design, the route has conspicuously little bike traffic. I could speculate on why Dexter succeeded and Broadway failed. But the question is, can our transportation departments make bike infrastructure which people actually use to get around. Since bikes are compact, good for peoples health, and good for the environment, infrastructure should be made with them in mind. That being said, they cannot be counted on to provide more than a transportation niche in our current infrastructure and cultural reality.

Another aspect of transportation infrastructure is walking. As a city grows denser, there tends to be more destinations in walking distance. Unfortunately walking can be made miserable if the streets are setup wrong. There are many ways to improve this. Corners can be made bulge out, so crossing the street at the corner involves less distance. Short walk paths can connect two close streets which don’t go through in cities initially built with no grid. There are many busy streets which currently have no sidewalk or sidewalk only on one side.[9] While our region has some exemplary pedestrian infrastructure, for example, Seattle has many staircases where the hills are too steep for street, there is huge room for improvement. As the region grows denser, walking becomes more important. Building and improving walking infrastructure is a cheap way to improve mobility and safety in a dense city.

What walking, cycling, and driving have in common is personal independence to use the infrastructure when needed. There is no marginal cost to run these facilities. Costs are almost entirely fixed investments. Despite the upsides of independence and fixed cost, these transport options have major downsides which can only be addressed through mass transport. Walking and cycling have the downside of being something only accessible to those who are fit and can show up wet or dirty. Cars have the fatal flaw of not scaling with growth. To address the need for high volume comfortable transportation, we need to go to mass transit, to be discussed in next weeks installment.