So Neil deGrasse Tyson, Bill Nye, and Elon Musk recorded a podcast where they discussed the issue of flying cars, which is really baked into the idea of alleviating the bogeyman of congestion. Now, these are three scientists/engineers/thinkers I couldn’t possibly have more respect for in the entire world. Musk goes on about the impracticality of flying cars (for good reason), but then suggests that 3-dimensional networks are the answer because it further separates transportation networks.
He’s somewhat right, but also very wrong. First, we’ve been building three dimensional networks for years, whether it’s subways, elevated rail lines, elevated freeways, or highway tunnels. Each of these are attempts (occasionally rightly) to make that one particular link from A to B as fast and efficient as possible, by eliminating intersections. However, applying this logic is an attempt to solve the wrong problem. It prioritizes the singular link over the network.
We’re blinded by the issue of congestion, only thinking about it from a car and speed mindset. And speed does not necessarily mean efficiency when proximity is much more efficient and often more pleasurable because it takes less energy and allows for other forms of travel if so desired. When we think about congestion only from a supply-sided perspective where our goal is improved Level of Service of a single road, and we make driving easier on that road, Braess’ Paradox kicks in, and as everyone acts in their own best interest of that perceived advantage they end up clogging that particular linkage while causing the rest of the system to underperform. Some places get invaded while some are abandoned. Neither is an ideal condition, let alone even a positive one to be in. It’s a system in imbalance and thus extremely volatile, unstable, and likely to collapse.
Scientists tend to dissect things and analyze the parts rather than seeing the value of the sum of the parts. They’re only seeing traffic from the lens that it’s always problematic rather than how, when, and where it is beneficial. At the end of the day, traffic of all forms are trips. Trips are social and economic activity in action. How do we make these trips as efficient as possible? Keep in mind that city-building is about balancing all needs and compromising based on priorities. Too often, one perceived need white washes all conversation – it’s usually, how do we move cars. However, when moving cars is the priority we undermine neighborhoods at the local level and cities at the macro-level if that is the only consideration.
In this case, they aren’t seeing the value of the two-dimensional network. When we spread out three dimensionally, we are taking energy off the street – the kind of patronizes retail and makes streets vibrant.
The answer isn’t three dimensionality but multi-modality, spreading trips around a variety of modes of travel by ensuring those modes are convenient, safe, and desirable. Thinking only about certain modes or certain corridors undermines multi-modality, is very high cost, the price of which is an incentive to the market to adapt to, take advantage of, and develop in a way that only uses that one mode or link. It entrenches car-dependence and thus ensures congestion and in many cases the abandonment of the street, which would be the real tragedy – the undermining of the true priority, the city.