In this online engineering PDH course, estimates are discussed of the crash reduction expected if various countermeasures are implemented with respect to traffic signals and pedestrian crashes. The estimates are presented as Crash Reduction Factors (CRFs).  Traffic engineers and other transportation professionals can use the information contained in this course when asking the following types of question: Which countermeasures might be considered at the signalized intersection of Maple and Elm Streets, an intersection that is experiencing a high number of crashes? What changes in the number of crashes are possible with the various countermeasures for traffic signals? Similarly, which countermeasures might be considered at the signalized intersection of Oak and Pine Streets, an intersection experiencing a high number of pedestrian crashes? What change in the number of pedestrian crashes can be expected with the implementation of the various countermeasures for pedestrian crashes? This course is based on the documents, “Traffic Signals” FHWA-SA-10-005, November, 2009, and “Toolbox of Countermeasures and Their Potential Effectiveness for Pedestrian Crashes,” FHWA-SA-104, May 2008, which can be accessed at  https://safety.fhwa.dot.gov/intersection/conventional/signalized/fhwasa10005/brief_5.cfm and https://safety.fhwa.dot.gov/ped_bike/tools_solve/ped_tctpepc/

Learning Objectives

• Define “crash reduction factors”;
• Identify, for traffic signals, CRFs for signal operations, signal hardware, and combination signal and other countermeasures;
• Identify, for pedestrian crashes, CRFs for signalization countermeasures, geometric countermeasures, and signs/markings/operational countermeasures;
• Explain the purpose, warrants for signal installation, advantages, and disadvantages of traffic signals; and
• Describe signal improvements that may decrease crashes.