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... xi CONTENTS 1 INTRODUCTION 3 CHAPTER 1 Introduction to Nonrecurrent Congestion and Travel Time Reliability 3 Nonrecurrent Congestion 7 Travel Time Reliability 8 Costs of Delay and Reliability 9 Reducing Nonrecurrent Congestion and Improving Reliability 11 CHAPTER 2 Selecting Design Treatments to Address Nonrecurrent Congestion 13 Choosing Treatments for Consideration 16 Evaluating and Comparing Treatments 17 CHAPTER 3 Catalog of Nonrecurrent Congestion Design Treatments 17 Medians 32 Shoulders 47 Crash Investigation Sites 50 Right-of-Way Edge 53 Arterials and Ramps 65 Detours 68 Truck Incident Design Considerations
From page 2...
... xii 72 Construction 75 Animal–Vehicle Collision Design Considerations 79 Weather 89 CHAPTER 4 Catalog of Secondary Treatments 89 Lane Types and Uses 106 Traffic Signals and Traffic Control 121 Technology 124 Emergency Response Notification 128 Weather 134 CHAPTER 5 Examples of Design Treatment Installations 134 Emergency Crossovers 135 Gated Median Barriers 136 Extra-Height Median Barriers 136 Drivable Shoulders 137 Alternating Shoulders 138 Emergency Pulloffs 138 Crash Investigation Sites 138 Ramp Turn Restrictions 139 Improvements to Detour Routes 142 Reduced Construction Duration 142 Improved Work Site Access and Circulation 144 Animal–Vehicle Collision Design Considerations 144 Contraflow Lanes: Evacuation 145 HOV Lanes and Toll Lanes 146 Work Zone Express Lanes 146 Ramp Metering 146 Fog Detection 148 Flood Warning System 149 Wind Warning System 150 REFERENCES Online version of this report: www.trb.org/Main/Blurbs/169768.aspx.

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