The first point is a way of understanding and prioritizing transportation issues utilizing the project management triangle. This is sometimes called the iron triangle consisting of equal segments: time, cost, and quality.
The first time I ever heard of such a simplification was when renovating a storefront in a mixed-use building, previously only used for old pool equipment storage, into a new office space. We tore out all of the walls to make an open concept, gutted it back to the studs, rearranged the kitchen, added a bathroom. When starting the project our general contractor (GC) said, "time, quality, and cost...you get to pick two of the three and we'll deliver it for you." We went with quality and cost. Even though we were already on the lease, we were able to get cheap enough rent that working out of coffee shops and homes was ok for another month or two.
The difference between project management and transportation is that from the user perspective with transportation you don't necessarily have to sacrifice any of the three legs of the stool. In any form of transportation (not necessarily the construction process, but rather the service provided to the end user, the citizenry), you still want to achieve all three. Where land costs plummet, such as in the rural countryside
An example of an Italian Passeggiata. Which is a quasi-official pedestrian route through the center of any Italian city that is also understood to mean the evening stroll many people take after dinner.
As a user however, you still want all three. You want most trips to be fast (not necessarily in terms of velocity but time), cheap (you don't want to expend a lot of energy and cost per trip), and ideally, you would like a high quality experience (it should be safe, pleasant, and scenic).
I ask, what achieves all three legs better than a nice walk? Whether in a countryside hamlet, a suburban neighborhood, or center city, all deserve to be as walkable as possible, because that achieves all three better than any other form of travel for the user. And then there are all the spin-off benefits such as personal health, increased tax base/density to infrastructure ratio, less physical wear and tear on the infrastructure, environmental benefits, increased commercial business, etc.
All of these can and should be walkable. There is simply more value and less cost to designing for more efficient movement, higher quality experience and increased safety of movement. To provide walkability (and the efficiency, convenience, pleasure, and safety therein), suggests a need for an increased subsidiarity, or hierarchy of jurisdiction where the lowest possible governing body dictates infrastructure design and priority via public process.
Movement in cities is good. It's a sign of an economy in action, vibrating within the tension that Charles Montgomery points out in his book Happy City that we're constantly vacillating between. We want to be near stuff. We want to be away from stuff. Often the same things in the same day. You want to be near points of economic exchange, markets or your job, a part of the hustle and bustle. Then you want to be away from it for a while. Prospect and refuge in action.
I think this is why I've always been drawn to time lapse video of cities in motion such as seen in the opening credits of Sherlock:
However, when you think of movement you're also thinking of energy expended. Certain types of movement require more energy (gasoline), embedded energy (pavement), increased pollution (belch), and congestion:
You'll never stop movement. Nor should we. Again, movement is the sign of a vibrant economy. When it stops, you have a problem. So you want that movement, especially where the movement and activity turns into the hyperactivity known as the socio-economic reactor we call cities, to be as time and energy efficient while being as elegant and safe as possible. High speed vehicular movement disrupts this vibrancy and density of activity that turns into something greater than the sum of parts, economic growth and improved quality of life. A bigger pie and a rising tide lifting all boats.
Highways are necessary. You heard me. But like Eisenhower knew (despite thinking of them primarily from a military/defense standpoint) and most cities around the world realized, they ought not throw the baby out with the bath water by running highways into the center of cities, severing highly complex and intricate socio-economic bonds.
That's why we must understand that there are two types of highways: Inter-city and Intra-city. Inter-city highways are those necessary for linking regional economies, such as Houston to DFW. They are necessary, provided they're also competing with overlapping regional linkages by air and rail. Intra-city highways are inner-city highways. These disrupt and disconnect more than they actually connect.
You can't have a conversation about improved and optimized cities and public infrastructure without understanding the two types of highways and which is appropriate and beneficial.
The reason is the point of any highway is free flow. Anything that interrupts free flow thereby diminishes the efficacy of the infrastructure. The closer you get to an urban core, the more friction there will be due to the more interchanges, exits, intersections, and crosswalks (as these frictional elements decrease in scale closer to the core).
Free flow and friction cannot coexist. They are antagonists. Thus in Lewis Mumford's terms, they are anti-city and city. Therefore, bodies politic must prioritize, which is more important: free flow or the friction of economic vibrancy. Otherwise, free flow will erode the friction until there is none. We must also remember what that free flow is in service towards, economic activity. If it is killing economic activity that it is supposed to be supporting, we have indeed entered a cancerous stage of infrastructure and in turn city building. Once you do that there is little value in the land except for drive-to theme park type uses, often requiring incredible levels of subsidy and/or charity.
This is becoming increasingly understood that the value of highway construction is becoming increasingly diminished. Perhaps to the point where it is destructive and adds negative value. One study suggests that the Return on Investment of new highway construction is approaching zero. That is we get 0 benefit from every dollar spent. And in transportation dollars, highways mean lots of dollars. For the value to get that low, we must question why we are doing it? Furthermore, in all likelihood, it is evidence of overshoot. We have built too many and too big of freeways at the expense of our socio-economic reactor, the city. And therefore, the right thing to do is to begin thinking about selective pruning in order to optimize connectivity for the sake of cities to continue to function efficiently. Lest that star might fade away.
Highway lane miles per capita within core city. No world class city is car-dependent.
However, for downtowns to maintain value they must remain connected to the global economy. So the infrastructure of global movement must be mitigated. Trains became subways and highways were aligned with floodplains, such as in Denver. The cost benefit analysis didn't pencil. Land and the economic activity on the land through urban cores was too value to displace, the costs were too high for the infrastructure, and the social costs of severing socio-economic bonds of community are immeasurable but still there nonetheless.
It's not about building infrastructure for infrastructure's sake. It's about optimizing cities to function better, as highly efficient and pleasurable engines for improved quality of life, opportunity, and advancement.
Some cities understood this. Some are still learning it.