Repost: "Urban Freeway" is an Oxymoron
Or perhaps it is more like a futon.
The first image shows the junction of I-10 and I-610 west of downtown Houston. The second image shows the central part of Angers, France at the same scale. Freeways do not facilitate urbanism and urban areas do not facilitate freeways.
Traffic engineers define freeway as a “limited access highway.” This is an important concept for traffic engineers. Two other important concepts are access and throughput. The first includes ingress and egress, or entering or exiting a transportation facility. Other kinds of access movements are turns and lane changes. In the case of a freeway, ramps take the place of turns and they are the only way to enter and exit. Since there are only periodic ramps to and from the freeway, this makes it a limited-access facility.
Traffic engineers are also concerned with the number of vehicles which can travel on a road within a period of time. These traffic volumes are called throughput. Therefore, a freeway is best understood as a road which prioritizes throughput compared to any other road type. Yet traffic engineers understand that throughput and access are competing values. Increasing access impedes both throughput and average vehicle speeds. More so than any other road type, a freeway, in its purest form, limits access in order to maximize throughput and average speeds.
On the other hand, urban places can be defined in terms of having high levels of access. Urban places are superior in access, or in facilitating short trips and movements. In order to achieve this high level of access, urban places need to restrict vehicle throughput and high speeds. Therefore, the very thing that characterizes urban places, access, is anathematic to a freeway. Furthermore, the very thing that characterizes a freeway, limited access, is anathematic to urban places. QED: “Urban Freeway” is an oxymoron.
Charles Marohn of the non-profit Strong Towns makes a similar argument. Instead of writing about freeways, he writes more broadly about roads and streets. Roads are high volume and high speed facilities with low access; streets are high access facilities with low throughput and speed. From this, he creates a portmanteau to refer to a compromise between these characteristics. Stroads attempt to compromise between a street and a road, but he argues, accomplish neither task very well. As such, stroads are like futons, which are neither good as beds, nor good as couchs.
I have noticed that in Seattle, unless we need to go more than about 5 miles, it is better to take surface streets at 25 mph than to take the freeway. It is a way to pass through the urban area, or leave the urban area, but useless for trips within the urban area. Houston inside the loop is similar, but not as clear-cut. But out in suburbia, local streets tend to be less useful and the freeway becomes the nexus. Of course, inside the loop one could call parts of Memorial a freeway.
Nicely put. The problem is that these are large and involved systems, so it's hard to just say "let's put the freeway 3 miles away, over here" because it would require reorganizing everything, pulling a string from the tapestry. Not that that has to be a bad thing...