Oxford University and Oxford City Council both signalled their support this week for the controversial approach to gridlocked roads, which involves getting rid of traffic lights and allowing vehicles, cyclists and pedestrians to mix together, sharing road space.

Widely used in Holland and Denmark, shared space is said to produce safer, smooth-flowing, low-speed traffic movement.

With roads no longer segregated, the whole approach depends on motorists, cyclists and pedestrians having to behave courteously towards each other.

This seems to be exactly the kind of policy Yorick mentioned in his comment. At any rate, I like the notion of a “shared space.” It sounds good and intuitively seems to fit a lot of situations, in which people engage in risky behavior and almost magically coordinate their actions to avoid some harm.

From a regulatory perspective, it would be interesting to know under what conditions such shared spaces work. Thinking briefly about it, at least two aspects come to mind:

1. Participants must have a strong self-interest in behaving considerately. In the case of road traffic, for instance, any accident is likely to adversely affect the other person as much as oneself. And even if an armored car hits a pedestrian without being damaged itself, there will normally be (legal) safeguards that allow the community to identify the wrongdoer by her license plate. Economists, I guess, would call this internalizing the negative externalities of one’s behavior.
2. The space must be designed in a way that allows people to communicate effectively and base their decisions on that communication. This seems to be the difference between a crowded injunction and a deserted highway. For instance, it will be very hard for a pedestrian to keep eye contact with a driver, who flies by with 170 km/h.

These are just two ideas, and there are probably some more conditions that must hold before a space is truly “shared.” Knowing what they are would give us a better idea of (a) in which situations we’d rather NOT regulate by imposing and enforcing rules and (b) how the law may help create the conditions, under which shared spaces work.

Couldn’t this be a model for some spaces on the Internet, where people engage in risky behavior and would coordinate their actions better if we managed to make the spaces shared ones?

What is interesting from the perspective of regulation is that there seem to be quite different mechanisms for coordinating traffic in different parts of the world. Two examples from my own experience: In my home country Germany, the default still seems to be coordination by traffic lights. The state sets rules as to who is allowed to cross the intersection at what time in what direction. Red light, stop. Green light, go. This is regulation by law, and most people abide by it – even if they are the only ones waiting at a deserted intersection in the middle of the night.

In southern Italy, my experience has been different. Traffic lights exist, but people do not seem to pay too much attention to them. Rather, they tend to slowly roll into the intersection and wait for reactions of other drivers. If the other driver slows down, this is taken as permission to cross. If not, people wait. If one driver notes that another driver cannot see her approaching, she honks. This is not regulation by law, but regulation by eye contact and honking.

Does one work better than the other?

I am not aware of any studies, but it would be interesting to know on what conditions each system depends. Isn’t the Italian way of coordinating traffic a real-world example of what others have called “peer production of governance” on the Internet? Under what circumstances does a decentralized social signaling system (eye contact and honking) trump a centralized law-based regime (traffic lights)? May it work particularly well in communications networks? And could the law do anything to foster it?

As to the latter question, Jonathan Zittrain mentioned after one of his recent lectures that Germany is gradually introducing roundabouts. As research (German only) indicates, this promises to be a big success – and an example of the law facilitating regulation by honking.