Service Design and Traffic Signs

Web Zen and the art of Road Traffic Design

I live on the border between France and Switzerland, and because of this I am constantly switching between two different approaches to the design of traffic flow. Traffic systems are possibly the single most common piece of service design that people interact with every day and as such comparing two forms is a good way to do a mental a/b test comparison of user behavior.

This sign shows who has right of way when the road narrows to a single lane. The way people interact with it says a lot about service design, rules and equality.

The design of the two countries’ traffic systems differ at the level of signage, rules of the road and the way road systems are funded and operated. In France the European model of blue signs for freeways and green for other roads is used, while Switzerland has the reverse, American model. In France, unlike Switzerland, there are still legacy rules from pre car eras, such as yielding to cars pulling onto a road, from the right, in front of you. In Switzerland, freeways are free once a yearly pass is bought and displayed in the windscreen, but in France, where ironically (since state run infrastructure is a French hallmark) much of the freeways are privately owned, they often require tolls.

However, there is one simple design difference in my frequent driving encounters, which possibly reveals something more general about rules, consensus and human behavior. I believe it says something about how to design other services, such as interactions on the Internet:

Who has right of way when the road narrows?

In France, one direction is often formally given priority by a sign whereas in Switzerland people are usually left to figure it out. My experience of how this works out is a nice simple example of how service design is as much about what you don’t design. Despite being anecdotal, it’s the result of repeated observation of a possible flaw in the French system, with the Swiss one acting as a control. A neutral standpoint — how appropriately Swiss.

Both the Swiss and the French versions often work. In the Swiss model people figure out who moves first, on-the-fly, like New York pedestrians, without fuss and in the French one, where it’s clear, people without the right of way follow the rules and stop to let oncoming traffic through the gap, even if they reach the intersection well before the person with the right of way.

This is where the subtlety comes in — in France, people tend to yield when they see an oncoming car with the right of way (i.e. not what you would imagine from French cultural stereotyping, people follow the rule to the letter), people with the right of way come to expect this. When there is a bend in the road so that people with the right of way are not visible, there is ambiguity, one half believes there is nobody coming to have to stop for but the other expects them to.

What results is a sense of self entitlement for those that have the right of way, such that they don’t ever slow down to people who haven’t seen them and are already committed to passing through a narrow gap. This results in conflict, and the conflict seems to be increased by a system which is designed to reduce it by its mere presence.

I’ve seen several arguments, one fight and one accident at road narrowings in France, all where the road bends, obscuring the view of oncoming cars with the right of way. I’ve never seen any in Switzerland, where there is no rule or signage.

This is not a case of user or cultural differences — the people on the Swiss and French roads in this area are the same, with the majority of French commuting to Switzerland and the majority of the population in this area of Switzerland not being Swiss.

The difference is in the mere presence of a rule and is a perfect example of how service design can operate better with the minimum of rules and maximum equality: people can achieve consensus on their own by being treated as equals.

Whether this has any scientific basis would need to be tested, however it nicely illustrates what in my experience has been the best approach to service design on the Internet — particularly with how to build and nurture communities without disputes — keep the rules simple and treat people as equal.

If there is Zen in the art of Motorcycle Maintenance, maybe there is in road signs too.