SFT Friction Testers

Friction is a key factor in road safety

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
  • Measures the peak or incipient slip friction in accordance with ASTM E1337
  • Identifies changes in surface friction due to deterioration, weathering, or other characteristics

The collected data is used to:

  • Test characteristics of applied surface treatments, such as high friction treatments (HFST)
  • Determine if roadways, intersections, and crosswalks have safe friction levels
  • Determine if a paved surface needs resurfacing or rehabilitation

Reduced pavement friction causes accidents and vehicle departures from the roadway.  Often, sections of road with poor friction can be repaired by applying high friction surface treatments (HFST).  Friction testing is an important tool departments of transportation use to identify safety problems and thereby to avoid accidents – and costly legal claims.

The trailer is available in single- and dual-sided versions.  The single-sided trailer applies the water and braking force on one side only, whereas the dual-sided unit alternates between the two sides to measure friction in both wheelpaths.


The unique benefits of ICC friction testers include:

  • 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
  • Calibration plate can be connected to the collection computer and integrated into the calibration procedure

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
  • ASTM E1337 Determining Longitudinal Peak Braking Coefficient of Paved Surfaces Using Standard Reference Test Tire
  • AASHTO T242 Frictional Properties of Paved Surfaces


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


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