Traffic Signals
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Traffic signals and the design of arterial facilities affect us daily as we travel to and from work, school, shopping and recreational facilities. There are an estimated 272,000 traffic signals in the United States and each has a profound impact on how safety and efficiently we share the space of intersections as we travel to our destinations.  Proper signal management can reduce congestion and save time for commercial and emergency vehicles, buses and the public.  Installing signals in the wrong locations can lead to unnecessary delay and decreased safely.
 
References
Signal Timing Manual
A concise, practical, user friendly and modular guide to signal timing practitioners, focusing on the principals of traffic signal timing, identifying sound timing practices, and a practical and comprehensive tabletop resource. 
Signal Timing Manual

ITE Traffic Signal Timing
There are about 300,000 traffic signals in the United States alone and over 75% of them could be improved by updating equipment or adjusting the timing. Traffic signal retiming is one of the most cost-effective ways to improve traffic movement and make our streets safer. Comprehensive signal retiming programs have documented benefits of 7-13% reduction in overall travel time, 15-37% reduction in delay and a 6-9% fuel savings.
ITE Traffic Signal Timing

FHWA Arterial Management Program
Arterial Management promotes the efficient and effective movement of people and goods and improves the safety of the traveling public and environment. The FHWA Arterial Management program covers three major focus areas: arterial management, traffic signal timing, and access management.
FHWA Arterial Management Program

Managing Traffic Flow Through Signal Timing Article
Traffic signal management can be defined as using improved tools, techniques, and equipment to make existing traffic signal control systems operate more efficiently. It helps improve air quality and reduce fuel consumption; reduce congestion and save time for commercial and emergency vehicles, buses, and the public; reduce the number of serious accidents; reduce aggressive behavior, including red-light running.
Managing Traffic Flow Through Signal Timing

Traffic Control Signal Needs Studies 
Studies and Factors for Justifying Traffic Control Signals. 
ITE Signal Warrant Brief

Signal Warrants - MUTCD
The study should consider the effects of the right-turn vehicles from the minor-street approaches. Engineering judgment should be used to determine what, if any, portion of the right-turn traffic is subtracted from the minor-street traffic count when evaluating the count against the above signal warrants. Engineering judgment should also be used in applying various traffic signal warrants to cases where approaches consist of one lane plus one left-turn or right-turn lane.
Signal Warrants - MUTCD

Traffic Detector Handbook
The Federal Highway Administration (FHWA) seeks to provide for pedestrians, bicyclists, and motor-vehicle users a surface transportation system that maximizes safety, mobility, and productivity. When FHWA was restructured in January 1999, core business units (CBU) and cross-cutting service business units were created. The restructuring was undertaken to emphasize the importance of highway safety and operations in how we do business.
Traffic Detector Handbook