High Friction Surface Treatments (HFSTs) are a safety countermeasure with exceptional skid-resistant properties intended to restore and maintain pavement friction in wet and dry conditions to reduce crashes. These properties are the result of the application of durable aggregates bonded to the existing pavement by a layer of polymer resin. HFSTs are effective in reducing crashes on horizontal curves and ramps, intersections, and pedestrian crossings, especially those with limited sight distance. HFSTs are also suitable for high traffic volume, conditions where the road will need to reopen to traffic quickly, and roads within an environmentally sensitive area. An FHWA advanced statistical study using empirical Bayes methodology shows a crash reduction of 57 percent for total crashes and a crash reduction of 83 percent for crashes on wet curves.

Maintaining the appropriate amount of pavement friction is critical for safe driving. In locations such as sharp horizontal curves and where vehicles may brake excessively, pavement surfaces may become prematurely polished, thereby reducing the available pavement friction. This friction reduction can contribute to vehicles losing control or skidding when they speed, turn abruptly, or brake excessively. HFST can restore safe friction levels to polished pavement.

Additionally, compared to vehicles driving on a tangent section of road, vehicles traversing horizontal curves require a greater side (lateral) force friction and vehicles at intersections require greater longitudinal force friction. These areas may need greater-than-normal pavement friction.

HFST technology is unique in its ability to address site-specific issues and may also be beneficial at:

  • High volume intersection approaches,
  • Interchange ramps,
  • Bridges, and
  • Selected segments of interstate alignments.

In New Jersey, the technology has been applied in various locations around the state. As per the guidelines,  HFST must be applied to pavements in “good” or better condition (i.e. with no cracking or rutting). While effective in reducing crashes at these locations, studies conducted at the tests sites showed premature deterioration, likely due to underlying undetected issues at the test site.  The study, conducted by researchers at the Center for Advanced Infrastructure and Transportation developed an effective prescreening tool that assesses the compatibility of asphalt and epoxy. The study also explored High Friction Chip Seal as an alternative to HFST. In a case study, an asphalt-based binding system was shown to be more compatible with the pavement than epoxy resin.

To learn more about the research, you can download a copy of the presentation here.