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Virginia Department of Transportation

Virginia Department of Transportation Guardrail Installation training Manual --GRIT-- Procedures and Practices for the Design, Installation, Replacement, and Repair of Guardrail and Crash Terminals August 2017 TABLE OF CONTENTS CHAPTER 1: INTRODUCTION TO ROADSIDE SAFETY A. The Need for Barrier training .. 1- 1 B. Clear Zone .. 1- 1 C. Barrier 1- 4 D. Barrier Flare Rates, Runout Length, and Shy line .. 1- 6 E. Length of Need .. 1- 7 F. Guardrail Testing Requirements .. 1- 8 G. Deflection .. 1- 8 H. Soil Backing .. 1- 10 I. Barriers on Slopes .. 1- 10 J. Curb Use with Guardrail .. 1- 10 K. Measuring the Height of Guardrail Systems .. 1- 11 CHAPTER 2: STANDARD GUARDRAIL SYSTEMS A.

A. NEED FOR BARRIER TRAINING . 1. Annually in the US, there are over 40,000 fatalities on our nation’s highways; more than half of them occurred as a result of a Roadway Departure- (RwD) crash. RwD Crashes are defined as a single vehicle leaving the roadway. 2. Guardrail fatalities Over 1,500 of the R- wD fatalities are caused by a roadside

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1 Virginia Department of Transportation Guardrail Installation training Manual --GRIT-- Procedures and Practices for the Design, Installation, Replacement, and Repair of Guardrail and Crash Terminals August 2017 TABLE OF CONTENTS CHAPTER 1: INTRODUCTION TO ROADSIDE SAFETY A. The Need for Barrier training .. 1- 1 B. Clear Zone .. 1- 1 C. Barrier 1- 4 D. Barrier Flare Rates, Runout Length, and Shy line .. 1- 6 E. Length of Need .. 1- 7 F. Guardrail Testing Requirements .. 1- 8 G. Deflection .. 1- 8 H. Soil Backing .. 1- 10 I. Barriers on Slopes .. 1- 10 J. Curb Use with Guardrail .. 1- 10 K. Measuring the Height of Guardrail Systems .. 1- 11 CHAPTER 2: STANDARD GUARDRAIL SYSTEMS A.

2 Guardrail Requirements .. 2- 1 B. VDOT NCHRP 350 Guardrail Systems .. 2- 1 1. VDOT 2- 1 2. VDOT GR-8, GR-8A, GR-8B, GR-8C .. 2- 1 3. VDOT GR-2, GR-2A .. 2- 3 4. VDOT MB-5, MB-3 .. 2- 4 C. VDOT MASH Guardrail Systems .. 2- 4 1. VDOT GR-MGS1, GR-MGS1A .. 2- 4 CHAPTER 3: STANDARD GUARDRAIL TRANSITIONS A. Weak Post Cable to Strong Post W-beam (GR-3 to GR-2).. 3- 1 B. Weak Post W-beam to Strong Post W-beam (GR-8 to GR-2) . 3- 1 C. Strong Post W-beam to Rigid Object (GR-2 to GR-FOA) .. 3- 2 D. Guardrail Attachment to Temporary Concrete Barrier .. 3- 4 E. Reducing W-beam Guardrail Deflection .. 3- 4 MASH Transitions .. 3- 4 A. NCHRP 350 W-beam to MASH W-beam (GR-MGS4).

3 3- 4 CHAPTER 4: GUARDRAIL TERMINALS A. NCHRP 350 Terminal Requirements .. 4- 1 B. VDOT Approved NCHRP 350 Terminals .. 4- 1 1. Cable Terminals (GR-3) .. 4- 1 2. Weak Post W-beam Terminals (GR-8 Type II) .. 4- 2 3. Strong Post W-beam (GR-6, GR-7, GR-9) .. 4- 2 4. Median Barrier Terminal (GR-9) .. 4- 5 5. Terminals for Curbed Sections .. 4- 6 6. Trailing End Terminals (GR-11) .. 4- 6 7. Bullnose Terminal .. 4- 6 C. Site Grading .. 4- 6 D. Breakaway Cable Anchorage 4- 9 E. VDOT Approved MASH Terminals .. 4- 10 1. Strong Post W-beam (GR-MGS2) .. 4- 10 2. Trailing End Terminal (GR-MGS3) .. 4- 10 CHAPTER 5: SPECIAL GUARDRAIL TREATMENTS A. Guardrail at Low Fill Culverts (GR-10) .. 5- 1 B.

4 Extra Blockouts (GR-INS) .. 5- 1 C. Radial Guardrail 5- 1 D. High Tension Cable Systems .. 5- 1 CHAPTER 6: BARRIER DELINEATION A. Longitudinal Runs .. 6- 1 B. Terminals .. 6- 1 CHAPTER 7: GUARDRAIL INSTALLATION REFERENCES APPENDIX 1: ACRONYMS & GLOSSARY LIST OF FIGURES AND TABLES FIGURE 1: COMPARATIVE RISK WARRANTS FOR EMBANKMENTS .. 1- 5 FIGURE 2: DESIGN APPROACH BARRIER LAYOUT VARIABLES (LON) .. 1- 7 FIGURE 4: RECOMMENDED BARRIER PLACEMENT FOR OPTIMUM PERFORMANCE .. 1- 9 FIGURE 6: GUARDRAIL HEIGHT RELATIVE TO SHOULDER/ CURB .. 1- 11 FIGURE 7: STANDARD GR-3 TO STANDARD GR-2 TRANSITION .. 3- 1 FIGURE 8: STANDARD GR-8 TO STANDARD GR-2 TRANSITION .. 3- 1 FIGURE 9: STANDARD GR-FOA-1.

5 3- 2 FIGURE 10: STANDARD GR-FOA-2 .. 3- 3 FIGURE 11: STANDARD W-BEAM TERMINAL CONNECTOR (GR-HDW) .. 3- 3 FIGURE 13: SUGGESTED ROADSIDE SLOPES FOR APPROACH BARRIERS .. 4- 8 FIGURE 14: GR-MGS2 LIMITED USE SITE PREPARATION .. 4- 11 FIGURE 15: NESTING OF W-BEAM RAIL FOR LEFT OUT POST (GR-10) .. 5- 2 TABLE 1: FIRST HARMFUL EVENT FIXED-OBJECT FATALITIES BY OBJECT TYPE .. 1- 2 TABLE 2: CLEAR ZONE DISTANCES .. 1- 3 TABLE 3: DESIGN PARAMETERS FOR ROADSIDE BARRIER LAYOUT .. 1- 6 CHAPTER 1 INTRODUCTION TO ROADSIDE DESIGN Page 1-1 We Keep Virginia Moving! CHAPTER 1 INTRODUCTION TO ROADSIDE DESIGN A. NEED FOR BARRIER training 1. Annually in the US, there are over 35,000 fatalities on our nation s highways; more than half of them occur as a result of Roadway Departure- (RwD) crashes.

6 RwD Crashes are defined as a single vehicle leaving the roadway. 2. Guardrail fatalities - Over 1,500 of the RwD fatalities are caused by a roadside barrier as the first harmful event. 3. In Virginia , about 2/3 of all fatalities are the result of R wD crashes. 4. The Virginia Strategic Highway Safety Plan is committed to reducing fatalities and serious injuries due to crashes. 5. Complexity of barrier systems and safety devices should be taken seriously. 6. Roadside barriers are hazards! Should only be used as a last resort. 7. Barrier standards and specifications are constantly changing and are based on vehicle designs and popularity, which affects the functionality of the barrier systems.

7 Testing criteria changes are also made based on current vehicle designs. B. CLEAR ZONE Clear Zone definition: The total roadside border area, starting at the edge of the traveled way (thru-lane), available for safe use by errant vehicles. 1. Each Location/Roadway has to be reviewed and the Clear Zone determined. 2. Generalized DESIGN CZ distances - Based on speed, traffic volume and cros-section/slope (see Table 2). 3. Principle - Provide the maximum, cost-effective clear zone. Any non-removable or non-breakaway obstacle within the design clear zone should be considered for shielding with a barrier system. The designer should strive for consistency along any section of roadway.

8 Clear Zone is provided for motorist safety and should not be confused with Minimum Lateral Offset , as discussed in the VDOT Road Design Manual. Clear Zones should be provided for all roadways, including curbed sections. GRIT Manual v. Chapter 1 Page 1-2 We Keep Virginia Moving! Table 1: FIRST HARMFUL EVENT FIXED-OBJECT FATALITIES ( Virginia 2011-2015) BY OBJECT TYPE Fatal Highway Crashes in Virginia 2016 763 deaths ( >2 per day) Approx. 500 were Roadway Departure Crashes (RwD) Primary and Secondary roads accounted for 65% of the RwD fatalities 3,800 serious injuries as a result of RwD crashes Trees are the leading cause of fatal crashes 10% 12% 18% 16% 5% 16% 22% 1% GRIT Manual v.

9 Chapter 1 Page 1-3 We Keep Virginia Moving! Table 2: SUGGESTED CLEAR ZONE DISTANCES (FROM EDGE OF THRU-LANE) Design Speed Design ADT FORESLOPES (Fill) BACKSLOPES (Cut) 6:1 or flatter 5:1 to 4:1 3:1 3:1 4:1 to 5:1 6:1 or flatter 40 MPH or less Under 750 7-10 7-10 * * 7-10 7-10 7-10 750-1500 10-12 12-14 * * 12-14 12-14 12-14 1500-6000 12-14 14-16 * * 14-16 14-16 14-16 Over 6000 14-16 16-18 * * 16-18 16-18 16-18 45-50 MPH Under 750 10-12 12-14 * * 8-10 8-10 10-12 750-1500 14-16 16-20 * * 10-12 12-14 14-16 1500-6000 16-18 20-26 * * 12-14 14-16 16-18 Over 6000 20-22 24-28 * * 14-16 18-20 20-22 55 MPH Under 750 12-14 14-18 * * 8-10 10-12 10-12 750-1500 16-18 20-24 * * 10-12 14-16 16-18 1500-6000 20-22 24-30 * * 14-16 16-18 20-22 Over 6000 22-24 26-32* * * 16-18 20-22 22-24 60 MPH Under 750 16-18 20-24 * * 10-12 12-14 14-16 750-1500 20-24 26-32* * * 12-14 16-18 20-22 1500-6000

10 26-30 32-40* * * 14-18 18-22 24-26 Over 6000 30-32* 36-44* * * 20-22 24-26 26-28 65-70 MPH Under 750 18-20 20-26 * * 10-12 14-16 14-16 750-1500 24-26 28-36* * * 12-16 18-20 20-22 1500-6000 28-32* 34-42* * * 16-20 22-24 26-28 Over 6000 30-34* 38-46* * * 22-24 26-30 28-30 *When a site specific investigation indicates a high probability of continuing crashes, or when such occurrences are indicated by crash history, the designer may provide clear zone distances greater than the clear zone shown in table 2. Clear zones may be limited to 30 feet for practicality and to provide a consistent roadway template if previous experience with similar projects or designs indicates satisfactory performance.


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