Road traffic is a great example: absent other incentives, I’m always going to choose the fastest route home that is available to me, even though taking a longer, more circuitous route would help spread out traffic and ease congestion for other drivers across my city. Traffic engineers have long assumed that the Nash equilibrium describes real-world rush hours pretty well.
In fact, mathematical studies and behavioral experiments dating back to the 1960s have shown that the collective delay is almost always worse in the Nash equilibrium, a.k.a. “user-optimized” driving scenario, compared to a world where drivers worked as a team for smoother traffic overall. Imagine a centralized transportation planner who assigned commuters their routes based on what was going to most benefit everybody. That god-like figure could impel some drivers to protract their journeys in order to improve the overall flow and decrease the cumulative time spent in traffic.
In this “system-optimized” equilibrium, our trips would be less harried on average: One widely cited 2001 paper by computer scientists at Cornell found that a network of “user-optimized” drivers can experience travel times equivalent to what a network of “system-optimized” drivers would experience with twice as many cars. Transport engineers call the difference between selfish and social equilibria the “price of anarchy.”
Perhaps the best approach to the future of traffic starts with redefining the problem we’re trying to solve. For most of the 20th century, the principal concern of transportation economists was to reduce travel time across a given distance. But getting as many people as possible to and from work, school, and shopping—period—might be the more important task. If the goal is reframed as increasing access, rather than increasing speed, then the answer involves more than traffic apps and vehicle transponders. Land use patterns would have to be rethought so that people can live closer to the destinations they care about. People should be able to walk as much as they want to, and use bikes, scooters, buses, and trains. Autonomous vehicles, if they come, ought to be carefully folded into the mix with care so as not to double down on congestion and carbon emissions.
The solution hints that this is a much larger issue than apps and whether they should be held responsible by the public. The underlying issue may be this: are Americans generally willing to set aside their own personal priorities in favor of societal arrangements that can benefit more people on the whole?
Americans like to drive and it is baked into the American way of life. One of the reasons Americans like their own vehicles is that it offers independence and control. Rather than relying on a set schedule or having or riding with other people or supporting big systems, Americans like the idea that they can get into their vehicle at any time and go wherever they want. They may not actually do this much – hence, we get fairly predictable rush hours when everyone is trying to go places at the same time – but individual vehicles provide options in a way that mass transit does not.
Making the switch over to systems rather than individual options – including mass transit – requires submitting parts of life to a collective that cares less about individuals and more about the whole. This same debate is playing out in other arenas such as how healthcare should be organized or whether wealth inequality should be addressed. If the favored outcome is individual choice, it is hard to move people toward collective approaches. Even if thinking of traffic and transportation as a larger system means that more people might be stuck less in traffic, the individual participant may not gain that much or may lose the feel of control. Access for all is a hard sell when many like their individual choices (even as they bemoan congestion).
It might take decades or generations before a significant shift away from individual drivers might occur. Indeed, more than just apps can continue to promote individual approaches to driving: ride-sharing still is largely an individual act and the private nature of self-driving cars might just make the choice to drive even easier for some.