June 14, 2012

In My Opinion: Ignoring study sets dangerous precedent


---- — In light of the recent decision to reinstall a traffic light at the intersection of Elm and Margaret streets, I felt compelled to clarify serious misconceptions that persist about traffic signals.

The basic question that must be answered is: Will this intersection operate better with or without a traffic signal?

First and foremost, traffic signals are used to assign vehicular and pedestrian rights-of-way. They are used to promote the orderly movement of vehicular and pedestrian traffic and to prevent excessive delay to traffic.

The idea that an intersection is any safer due to a traffic signal is not necessarily true, as is shown in a multitude of studies and data. In fact, unjustified or improper traffic-control signals can result in one or more of the following disadvantages: excessive delay, excessive disobedience of the signal indications, increased use of less adequate routes as road users attempt to avoid the traffic-control signals and significant increases in the frequency of crashes (especially rear-end crashes).

Secondly, a traffic signal does not resolve all traffic problems at an intersection. Traffic-control signals are often considered a panacea for all traffic problems at intersections. This belief has led to the installation of signals at many locations where they are not needed and where they may adversely affect the safety and efficiency of vehicular, bicycle and pedestrian traffic.

Lastly, traffic signals should not be installed unless one of the warrants specified by the Manual on Uniform Traffic Control Devices has been satisfied. An engineering study must be conducted to determine whether the traffic signal should be installed.

The installation of a traffic signal requires sound engineering judgment and must balance these sometimes conflicting goals: moving traffic in an orderly fashion, minimizing delay to vehicles and pedestrians, reducing crash-producing conflicts and maximizing capacity for each intersection approach.

Traffic signals should not be arbitrarily removed or installed with disregard to the findings of an engineering study. The Manual on Uniform Traffic Control Devices is the standard behind traffic control by which state DOTs and municipalities are required to abide. It is imperative to follow these standards to ensure safety and efficiency exists throughout the transportation network, not to mention avoiding liability.

Many of us have opinions, as drivers, about what type of control that we think an intersection ought to have; however, these conjectures do not substitute for proper engineering evaluation, and we should not deviate from these standards due to individual perceptions or political pressure.

I believe we are setting a dangerous precedent of undermining the work of our city management. As City Council members, it is not possible, nor is it expected for us to be experts in all aspects of the fields that we legislate and oversee. For this very reason, we have a competent and knowledgeable group of professional city managers, and we commission professional consultants from time to time.

In this case, the city commissioned a professional engineering consultant in 2005 to evaluate the intersection at Margaret and Elm streets. During the recent discussion, I heard some say that they have no idea why the signal was taken out. Perhaps if you read the engineering study, you will know the answer, which is that there is simply not enough traffic to warrant a signal.

Others say that we know better than someone at New York State DOT. Again, read the study. The city hired a consultant to perform the study that was disregarded, not the DOT.

As a council, we are all in agreement that there exists a visibility problem as vehicles approach Margaret Street from Elm due to parking spaces on Margaret Street very close to the intersection. Our resolution should have addressed the root cause of the problem and improved the sight lines for motorist approaching the intersection by removing two or three parking spaces.

The removal of parking spaces would have been the prudent and safe solution for this intersection and at virtually no cost. The recent council decision was not only a poor choice, but, without removing the parking spaces to improve sight distance, it’s quite likely that the signal will not help.

Mark Tiffer is the Ward 2 councilor on the City of Plattsburgh Common Council.