SFT Friction Testers

Friction is key in road safety!

Managing pavement friction on existing roads is critical for safety. Reduced pavement friction causes accidents and vehicle departures from the road. Through advances in roadway materials, road sections today with poor friction can be repaired by applying high friction surface treatments (HFST). To keep road users safer and to achieve “zero deaths” safety goals, most transportation agencies want to identify current and potential safety problems proactively. This also helps avoid costly legal claims.

Locked wheel friction testers measure pavement friction accurately and directly.  The friction coefficient is calculated between a tire on the specialized trailer as it skids over wet pavement.  The truck carries the water tank and control system.  The system:

  • Measures the average friction coefficient in accordance with ASTM E274
  • Identifies changes in surface friction due to deterioration, weathering, or other characteristics
  • Collects optional macrotexture data to help identify the “coarseness” of the pavement surface, known to influence friction

The collected data is used to:

  • Test characteristics of applied surface treatments, such as HFST
  • Determine safe friction levels on roadways, intersections, and crosswalks
  • Identify resurfacing or rehabilitation needs for current paved surfaces

The trailer is available in single- and dual-sided versions

  • Single-sided trailer – Applies the water and braking force on one side only
  • Dual-sided trailer- Alternates between the two sides to measure friction in both wheelpaths


The unique benefits of ICC friction testers include:

  • Adheres to ASTM and AASHTO industry standards
  • Maintenance-free, coil-over shocks instead of air-adjustable shocks
  • Check valves installed before the electric valve to save water, which translates to fewer refill stops
  • Proprietary racing-style aluminum brake calipers 
  • Proximity switch for DMI, which enables a field fix versus down time in the garage
  • Aluminum fenders and hoods with Kevlar coating
  • Top-down access to trailer suspension system
  • Rapid fire mode option for closer spacing between tests; faster lockup reduces water usage
  • User friendly and time efficient
  • Innovative development since 1975

    Meets Industry Standards

    • ASTM E274 Skid Resistance of Paved Surfaces Using a Full-Scale Tire
    • ASTM E501 Standard Rib Tire for Pavement Skid-Resistance Tests
    • ASTM E524 Standard Smooth Tire for Pavement Skid-Resistance Tests
    • AASHTO T242 Frictional Properties of Paved Surfaces

      SFT SR

    Our standard range safety friction tester capable of holding 350 gallons (1,300 L) of water.

      SFT XR

    Our extended range safety friction tester capable of holding 1,200 gallons (4,500 L) of water.