USA Banner
  U.S. flag
              An official website of the United States government Here's how you knowOfficial US Government Icon
              **Official websites use .gov**A **.gov** website belongs to an official government organization in the United States.
            Secure Site Icon
              **Secure .gov websites use HTTPS**
                  A **lock** ( A locked padlock ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. 
 U.S. Department of Transportation Icon United States Department of Transportation
 Search DOT
            Search
                    About FHWAFHWA Organization
                Headquarters Offices
                Field Offices
                Strategic Plan
                Business Opportunities
                Staff Directories
                Careers
                Highway History
                Contact UsProgramsAcquisition Management
                Civil Rights
                Federal Lands Highway
                Infrastructure
                Innovative Program Delivery
                Operations
                Planning, Environment, and Realty
                Policy
                Research, Development, and Technology
                Safety
                Browse by TopicsResourcesCore Highway Topics
                Federal Aid Essentials
                Automation
                Complete Streets
                Laws and Regulations
                Policy & Guidance Center
                Section 508
                Publications and Statistics
                Professional Development
                National Highway Institute
                Resource Center
                Accessibility Resource Library
                FHWA Research LibraryNewsroomPress Releases
                Speeches & Testimony
                Photos
                Videos
                Media ContactsMenu FHWA Highway Safety Programs Home
                        High Friction Surface Treatment Curve Selection and Installation Guide May 2016


            
            In This Section
        Pavement Friction
                Friction Management
                Continuous Pavement Friction Measurement (CPFM)
                Traditional Friction Treatments
                High Friction Surface Treatment
                Case Studies and Noteworthy Practices
                FAQs, Links, and Other Resources
                
                Appendix A – HFST Curve Identification Summary
The process of identifying curves for HFST varies by agency. Questions agencies may ask while identifying candidate curves for HFST include:

Is there an existing safety issue?
	Is wet weather contributing to the issue?
		Is the friction demand outweighing available friction?
	Are speed differentials, the difference between the tangential posted speed limit and the curve advisory speed, contributing to crash frequency?
	Are prior low-cost treatments not sufficiently effective?These questions can be answered and navigated using a decision tree. Figure 11 displays a possible decision tree scenario that agencies may use when considering HFST. After evaluating the effectiveness of multiple HFST implementations, agencies may migrate from spot treatments to systemic implementation, which both streamlines the HFST design process and reduces costs. Table 3 displays the HFST feasibility criteria considered by four States, each of whom have or are planning to implement HFST at 25 to 150 locations. Agency's process may vary from information presented in this chapter.

**Table 3. HFST Considerations by Agency.**
	Agency
			Crash Frequency
			Wet Crashes
			RwD Crashes
			Skid/Friction Values
			Curve Speed Diff.
			Prior Treatments Installed
			Pavement Quality
			Spot/Systemic Identification and/or ImplementationSCDOT
			X
			X
			X
			X
			X
			X
			X
			**Systemic** – State RwD PlanCaltrans
			X
			X
			X
			
			
			X
			X
			**Spot Treatment** Bundles projects into large contractsPennDOT
			X
			X
			
			X
			X
			X
			X
			**Systemic** – Statewide HFST initiativeTDOT
			X
			X
			X
			X
			
			X
			X
			**Systemic** – Statewide HFST initiativeKYTC
			X
			X
			X
			X
			
			X
			X
			**Systemic** – Statewide HFST initiative

**Figure 11. Identifying HFST Appropriateness and Feasibility on Horizontal Curves Flow Chart**Decision matrix to assist in identifying when HFST treatment may be appropriate. A note indicates that the user should see the HFST Construction Specifications for surface preparation and weather limitations.
      
  Book traversal links for Appendix A – HFST Curve Identification Summary
      ‹ 6. Conclusion
                    Up
                    Appendix B – Other HFST Potential Locations and Uses ›
                
                Book:High Friction Surface Treatment Curve Selection and Installation Guide May 2016
              1. Step 1: Identify Candidate Curves for HFST
                2. Step 2: Conduct Field Verification and Design
                3. Step 3: Select Aggregate and Binder Materials
                4. Step 4: Determine Application Method and Develop Specifications
                5. Step 5: Estimate Costs and Identify Funding
                6. Conclusion
                Appendix A – HFST Curve Identification Summary
                Appendix B – Other HFST Potential Locations and Uses U.S. DEPARTMENT OF TRANSPORTATION

**Federal Highway Administration**

1200 NEW JERSEY AVENUE, SE

WASHINGTON, DC 20590

202-366-4000Subscribe to email updates
                    About
  

        
              About FHWA
                Careers
                Org Chart
                Staff Directories
                Work with UsPrograms
  

        
              Acquisition Management
                Civil Rights
                Federal Lands Highway
                Infrastructure
                Innovative Program Delivery
                Operations
                Planning, Environment, and Realty
                Policy
                Research, Development, and Technology
                SafetyPolicies, Rights, Legal
  

        
              About DOT
                Accessibility
                Budget and Performance
                Civil Rights
                FOIA
                Information Quality
                No FEAR Act
                Office of Inspector General
                Privacy Policy
                USA.gov
                Web Policies and Notices
                Web StandardsNews & Events
  

        
              Newsroom
                Press Releases
                Speeches & Testimony
                Media Contacts
                Connect with Us