This is the Manual on Uniform Traffic Control Devices (MUTCD)is prepared and updated by the Federal Highway Administration of the U.S. Department of Transportation. It is the primary source for questions about traffic control devices. Warning: This is a book written by engineers for engineers. That doesn’t mean that civilians can’t read and understand it, but you should be prepared for detail.
Lots and lots of detail.
We use the MUTCD to help us evaluate requests for signs and signals on City streets. We gets requests every month for a new stop sign here or a new signal there. Citizens are often surprised that we don’t install the sign or signal simply at their request. Aside from the costs (signs are in the hundreds of dollars; signals are in the he hundreds of thousands of dollars), there are many reasons why we study and evaluate these requests.
It may not seem like it sometimes, but most drivers respect most traffic control devices. Because drivers are willing to modify their behavior when we ask them to, we need to make sure that we are asking them to modify their behavior for a good reason. Stop signs, for example, are often requested by citizens who want traffic slowed in their neighborhoods. But stop signs are not good tools to slow traffic. They sometimes even divert that traffic to other neighborhood streets, and speed it up as well.
This may be counter-intuitive, but traffic studies and statistics will bear it out. And I can assure you that, with the possible exceptions of the weather and major league baseball, no subject is studied more or generated more raw statistical data than traffic. If you want to know the answer to a traffic question, rest assured, it has been studied and answered. It’s out there somewhere.
So the most important issue we consider when deciding to place a new traffic sign is its possible effectiveness. Will it make traffic behave in a way that we want it to behave? The second is probably the cost, both installation and future maintenance. Finally, we also consider the aesthetics issue. The more signs we place in the environment, the more we dilute each sign’s individual ability to grab your attention. More and more signs also add to the everyday visual clutter of the public space that we must share together.
It can be very frustrating to citizens to not get the Yield or Stop or Children At Play sign they requested. I mean really, what’s the harm in the City just giving them what they have requested? So here’s what I’d say to that. If we don’t have to have another sign out there, and it’s not going to be effective anyway, then why spend the money on it and why add it to environment? Installing traffic control devices to quiet down an angry citizen might be good politics, but it is bad for traffic control in our City.
