The warranting process for traffic signals has evolved with changing technology and traffic needs over the last 60 years. The project's outcome is a set of comprehensive, uniform guidelines for conducting traffic signal warrant analyses. Based on these clarifying guidelines, the warranting process provides reliable, consistent results that offer a clear indication of whether the conditions justify further consideration of a traffic signal. The process leaves room for all evaluations that affect the decision to place or remove a traffic signal and promotes statewide consistency in the warranting process. The language of the warrants is vague, so an engineer in one district could be making very different assumptions from an engineer in another district.
Signal justification can be complicated and, often, misunderstood.
The new guidelines provide transportation officials with detailed information about conducting a traffic signal warrant analysis. They clarify issues open to interpretation, improve the consistency of decisions and provide a way to explain resulting outcomes. There are a lot of clarifications in the guidelines that traffic engineers probably know instinctively but have never seen officially interpreted. Uniform signal placement and operation lead to consistent driver recognition and potentially greater safety for all roadway users. When installation of a traffic signal is properly justified, and it operates effectively, the signal can have many advantages for a community.