Synthesis of Variable Speed Limit Signs

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U.S. Department of Transportation
Federal Highway Administration
Office of Operations
1200 New Jersey Avenue, SE
Washington, DC 20590

FHWA-HOP-17-003

May 2017

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Table of Contents

[ Foreword ] [ Notice and Quality Assurance Statement ] [ Technical Report Documentation Page ] [ SI Conversions ] [ Acronyms ]

EXECUTIVE SUMMARY
CHAPTER 1. INTRODUCTION
	SHORT DESCRIPTION
	HISTORY AND PREVIOUS RESEARCH
CHAPTER 2. RESEARCH METHODOLOGY
	LITERATURE REVIEW
	AGENCY OUTREACH
	SYNTHESIS AND ANALYSIS
CHAPTER 3. VARIABLE SPEED LIMIT STATE OF THE PRACTICE
	REPRESENTATIVE VARIABLE SPEED LIMIT SYSTEMS IN THE UNITED STATES
	VARIABLE SPEED LIMIT SYSTEMS USED FOR CONTESTION-BASED ACTIVE TRAFFIC MANAGEMENT
	VARIABLE SPEED LIMIT SYSTEMS USED FOR WORK ZONES
	VARIABLE SPEED LIMIT SYSTEMS USED FOR WEATHER
	DEACTIVATED VARIABLE SPEED LIMIT SYSTEMS IN THE UNITED STATES
	LESSONS LEARNED
CHAPTER 4. FINDINGS
	PLANNING AND POLICY
	DESIGN, DEPLOYMENT, AND STANDARDS
	OPERATIONS AND MAINTENANCE
	OUTCOMES
CHAPTER 5. CONCLUSION - BENEFITS AND CHALLENGES OF VARIABLE SPEED LIMIT SYSTEMS
	KEY BENEFITS
	KEY CHALLENGES
	VARIABLE SPEED LIMIT KEY CONSIDERATIONS
	FUTURE OF VARIABLE SPEED LIMITS
APPENDIX A. BIBLIOGRAPHY
APPENDIX B. AGENCY INTERVIEW SUMMARY

List of Figures

Figure 1	Photo. New Jersey Turnpike variable speed limit and variable message signing
Figure 2	Figure 2. Chart. Weather responsive system for OR 217

List of Tables

Table 1	Summary of variable speed limit data sources
Table 2	Description of the variable speed limit systems considered in the report
Table 3	Lessons learned by State agencies from variable speed limit implementations
Table 4	Fundamental variable speed limit infrastructure requirements
Table 5	Washington State Department of Transportation speed limit reference
Table 6	Variable speed limit system practices and field results