When Danielle was a little girl, she always wondered how the traffic lights knew when to turn red, yellow, and green as she traveled on the road with her family. If you are as curious as she was, go and slowly read this delightful rhyming book with a friend or two. Next time you are driving with your family, stop and look up at the traffic lights and they just might wave to you.

This report serves as a comprehensive guide to traffic signal timing and documents the tasks completed in association with its development. The focus of this document is on traffic signal control principles, practices, and procedures. It describes the relationship between traffic signal timing and transportation policy and addresses maintenance and operations of traffic signals. It represents a synthesis of traffic signal timing concepts and their application and focuses on the use of detection, related timing parameters, and resulting effects to users at the intersection. It discusses advanced topics briefly to raise awareness related to their use and application. The purpose of the Signal Timing Manual is to provide direction and guidance to managers, supervisors, and practitioners based on sound practice to proactively and comprehensively improve signal timing. The outcome of properly training staff and proactively operating and maintaining traffic signals is signal timing that reduces congestion and fuel consumption ultimately improving our quality of life and the air we breathe. This manual provides an easy-to-use concise, practical and modular guide on signal timing. The elements of signal timing from policy and funding considerations to timing plan development, assessment, and maintenance are covered in the manual. The manual is the culmination of research into practices across North America and serves as a reference for a range of practitioners, from those involved in the day to day management, operation and maintenance of traffic signals to those that plan, design, operate and maintain these systems.

Despite traffic circles, four-way stop signs, lights regulated by timers or sensors, and other methods, the management of urban intersections remains problematic. Consider that transportation systems have all the features of so-called complex systems: the great number of state and control variables, the presence of uncertainty and indeterminism, th

When the road signs take a vacation, chaos and hilarity ensue--and they quickly learn how important they are. School is ending for the summer, and the stick figures on the school crossing sign are jealous of all the vacation plans they hear the students making. The stick figures work hard--maybe they deserve a vacation, too! So they abandon their signpost and set off on an adventure, inviting along all the other underappreciated road signs they meet on the way. It's all fun and games for a while, especially when they stumble upon a fantastic amusement park. But the people they've left behind are feeling their absence, and soon there are traffic tangles and lost pedestrians everywhere. The signs are more important than they realized, and now it's time for them to save the day!

This document presents a synthesis of current information and operating practices related to roadside safety and is developed in metric units. The roadside is defined as that area beyond the traveled way (driving lanes) and the shoulder (if any) of the roadway itself. The focus of this guide is on safety treatments that minimize the likelihood of serious injuries when a driver runs off the road. This guide replaces the 1989 AASHTO "Roadside Design Guide."