Why do you stop at red lights?

I recently asked a co-worker this question when we were talking about law.  It went something like:

Me:  Why do you stop at red lights?

Her:  Because it’s the law.

Me:  You mean the law as in the rules on the books?

Her:  Of course.

Me:  Do you drive the speed limit?

Her:  Well close to it.

Me: But over it, right?

Her:  Well, yeah, doesn’t everybody?

Me:  Okay. Are you still sure that you stop at red lights because it’s a rule that’s written down?  You just admitted that you don’t follow another written down rule.

Her:  Not really.  So, why do I stop at red lights?

Me:  I’m going to give you a choice.  I can give you the answer and the way you look at the world may change.  Or, I will not give you the answer and you can go on believing the world around you behaves in a way that it does not.

Her:  Okay, quit the Matrix b.s. and tell me for crying out loud.

Me:  Well.  There’s a couple reasons you stop at a red light.  One is your own safety.  You know that you don’t stop at green lights.  And you know that nobody else does either.  So, if you ran red lights, the direct consequences could be great and you could do you and others serious harm.  The main reason you stop at red lights is because it pays off well for you to do so.

Her:  Okay.

Me:  Another reason is that at some point in time, the color red became associated with stopping in traffic.  No central body sat around and said red lights will be the standard for that.  It emerged somewhere as a practice and stuck.  As far as I know, most traffic laws are passed by city and state governments.  Yet, somehow, without a centralized standards committee on traffic signaling, red emerged as the signal for stopping and green for go.  And it’s just not in the U.S.  It’s pretty much everywhere there’s traffic — other countries, railroads, airport runways, boats and so forth.  So, that’s why you stop at the color red.  (This website claims that the traffic signal was adapted from the railroad by an innovative officer in Michigan).

Her: Okay.  So what’s your point?

Me:  My point is that you, like most people, think you stop at red lights because “it’s the law”.  It is in a sense, but not the sense you are thinking.  You are thinking of legislation, or the law that some governing body has written down on paper.

However, if we investigated all legislation, we’d probably find many “laws” that we break.

You stop at red lights because “it’s the law” in the sense that it’s an evolved social norm.  This norm evolved to help keep us safe.  And it works.  Do you know how I know it works?

Her: I bet you’re going to tell me.

Me: Because we still practice it and it more or less keeps hundreds of millions, if not billions of people safe.  I’m guessing if we looked into history, we might find that there were other things tried, but they didn’t work as effectively.

Roundabouts and cloverleafs, for example, also seem to be effective ways to handle intersections in traffic, the real estate and additional construction cost probably doesn’t make them as cost effective as traffic signals.

Laws are really developed in the crucibles of human interactions and emerge as social norms, customs and practices.

They rarely emerge from legislators or judges, even though most people think that’s exactly where they come from.

Her:  Gee.

This conversation was inspired by this lecture from Don Boudreaux:

The video is worth your time.  If you don’t have that kind of time to sit at the computer, then you can also download an EconTalk podcast from 2006 that’s essentially the same material.

Listen to it if you want to escape the Matrix.