http://safety.fhwa.dot.gov

Improving Pavement Friction for Safety at a 

Florida Signalized Intersection 

Project Case Study 

HFST Increases Friction to Reduce Intersection Crashes

The Tampa region of Florida Department of Transportation (FDOT) has a 

long history of using Road Safety Audits (RSAs) to assess potential safety 

enhancements at intersections. As part of a recent RSA, FDOT included

continuous pavement friction measurement (CPFM) data. With friction 

and crash data in hand, the RSA team was able to more closely examine 

pavement-related factors that could explain higher-than-average crashes 

at this intersection. In particular, the resolution of the CPFM1 data 

allowed the RSA team to posit that lower pavement friction when 

compared to the surrounding pavement was likely a significant factor 

under both wet and dry conditions at the critical approaches to the 

intersection stop line and crosswalk. In response, FDOT initiated a project to apply High Friction Surface Treatment (HFST)

to the intersection approaches and within the intersection itself. 

HFST is a proven safety countermeasure used specifically to reduce or 

prevent friction-related crashes. HFST significantly enhances 

pavement friction to reduce both wet and dry pavement skidding 

crashes at locations with high friction demand. While the benefits of 

HFST for horizontal curve and ramp applications are welldocumented2

, intersection applications have seen comparatively 

limited use to date in the United States. However, since HFST 

shortens stopping distance, it can reduce or prevent rear-end crashes 

at intersection approaches3 and potentially angle crashes within an 

intersection. FDOT is one State highway agency taking steps towards 

validating the use of HFST for intersection applications, and in July of 

2020 installed HFST at the intersection of SR 580 (Hillsborough Ave.) 

and Central Ave. in Tampa, Florida. From 2015-2020 there were approximately 13.5 crashes 

per year at this intersection, with the vast majority (86 percent) being dry pavement crashes 

and the predominant crash type (68 percent) being rear-end crashes. Just over 2,700 square 

yards of HFST were applied to the left-turn lane and two thru lanes during two consecutive 

nighttime installation operations, minimizing disruption to the traveling public. Friction 

testing after completion of the installation revealed that HFST more than doubled pavement 

friction at the intersection approach.

1 Federal Highway Administration. “Continuous Pavement Friction Measurement”. 2021. 

https://safety.fhwa.dot.gov/roadway_dept/pavement_friction/cpfm/

2 Merritt, D. K., Lyon, C. A., Persaud, B. N., and Torres, H. N. Developing Crash-Modification Factors for High-Friction Surface Treatments, 

Federal Highway Administration FHWA Research Report FHWA-HRT-20-061. McLean, VA. 2020. 3 FHWA. High Friction Surface Treatment at Intersections. Federal Highway Administration FHWA-SA-20-012. Washington, D.C. 2020.

HFST more than 

doubled pavement 

friction at Central Ave. 

Before HFST: FN40R = 37 

After HFST: FN40R = 79 

HFST on Hillsborough Ave. at Central Ave. 

(Source: Florida DOT)

Application of HFST to Hillsborough Ave. using fullyautomated installation. (Source: Florida DOT)
http://safety.fhwa.dot.gov

Increased Friction Improves Stopping Behavior at Intersections

While the original intent was to reduce friction-related crashes at this intersection, 

HFST has demonstrated potential safety benefits to pedestrians by reducing crosswalk 

incursions through improvement in stopping behavior. The Center for Urban 

Transportation Research (CUTR) at the University of South Florida analyzed stopping

behavior through a review of video captured at the intersection. Specifically, the researchers documented crosswalk 

incursions while the traffic light was red at three different periods of the day (morning and afternoon rush hour and late 

night). Stopping behavior was analyzed prior to HFST application, then at one month and nine months after application. 

This analysis revealed a 26-percent overall reduction in improper stopping behavior one month after HFST application and 

31 percent reduction nine months after application. While crash reduction benefits have not yet been quantified for this 

intersection, a reduction in crosswalk incursions demonstrates another important safety benefit of HFST for intersection 

applications. A holistic approach to CPFM —which for this case study included starting with continuous pavement friction 

measurement, incorporating friction data into safety assessments, and implementing friction improvements—can benefit 

all users. 

Additional Resources

• FHWA Every Day Counts, Frequently Asked Questions – High Friction Surface Treatments 2021.

https://www.fhwa.dot.gov/innovation/everydaycounts/edc-2/pdfs/hfst_faqs.pdf

• FHWA Every Day Counts, A Road Surface Treatment for Critical Safety Spot Locations that Helps Vehicles Stay in Their

Lane. https://www.fhwa.dot.gov/innovation/everydaycounts/edc-2/pdfs/hfst_brochure.pdf

• High Friction Surface Treatments (HFST) website:

https://safety.fhwa.dot.gov/roadway_dept/pavement_friction/high_friction/

Crosswalk incursions 

decreased 31 percent 

after HFST 

application. 

Results from analysis of stopping behavior at Central Ave. intersection before and after HFST application. (Source: CUTR)

** significant at a 

95% confidence level

* significant at a 90%

confidence level

FHWA-SA-22-09