Stop signs

Talking about stop signs is public discourse in miniature.  Few things are more ubiquitous than the white-on-red octagonal signs.  To engineers, they are traffic control devices governed by the MUTCD--the Manual on Uniform Traffic Control Devices.

The MUTCD is exactly the thrilling page-turner you'd expect from engineers writing about inanimate objects.  A far more readable Cliff's Notes version can be found here, with the more racy title, "Speed Control in Residential Areas."

Here's an excerpt:

"Residents’ complaints are usually accompanied by a proposed solution to the speeding problem...stop signs. Traffic officials respond that stop signs installed to control speeding: (a) don’t work, (b) are frequently violated, (c) are detrimental to safety, (d) are not warranted in the Manual* and, (e) actually increase speeds between stop signs. When residents are told that stop signs are not the answer to the speeding problem, they feel they must fight city hall to get them installed. A confrontational relationship is established between residents and traffic officials and the stop sign becomes a “trophy” which is awarded to the winner of the confrontation. Solving the speeding problem becomes secondary to winning the “trophy”. The end results of this process are: (1) unhappy citizens, (2) continued complaints and requests for more stop signs, (3) increased political pressure and, (4) often, approval of stop sign installations to bring the controversy, temporarily, to an end."

Obviously, the authors have experienced the unmitigated joys of a public debate over putting stop signs at the corner of <insert random tree name> avenue and <insert random number> street.

Like the problems that occupy most of local governments' time, speeding is complex, widespread, and slippery.  And like many issues, it's only a problem when "other people" do it.  For those who doubt cosmic justice, I offer the example of the resident who was complaining most loudly about speeding in their neighborhood being the first to receive a traffic citation on the same street for <wait for it> speeding!  To add sauce to the goose, most speed studies come back showing the perceived speeding is not nearly as excessive as portrayed.

People want simple, straightforward solutions to problems they perceive.  Few pieces of painted metal are more simple and straightforward than a stop sign.  Engineers and pretty much anyone who believes in the Enlightenment prefer rational solutions to specific, real problems.  One can have an intuitive notion that stop signs make a street safer... but belief is not the same as proof.  And the expenditure of public funds and governance of public facilities--even on something as modest as a stop sign--should be governed by rational thought, engineering best practices, and scientific evidence.

The great advantage of scientific discourse is that someone eventually wins, understanding that all such victories are temporary, good only until better data, measures, or testing comes along.  We no longer argue about whether the earth is flat (well, mostly). Theological debates, on the other hand, are endless absent one side eliminating the other.  If we can't agree to follow a rational process in putting up or taking down stop signs... how much chance do we have solving much larger problems?