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In-Service Performance Evaluation Resources (ISPE)

Federal Highway Administration Pilot In-Service Performance Evaluation of Guardrail End Treatments

The Federal Highway Administration (FHWA) Office of Safety Research and Development is conducting a pilot in-service performance evaluation (ISPE) of the most widely used energy absorbing guardrail end terminals (GETs) in the United States, specifically: ET-Plus, ET-2000, Flared Energy Absorbing End Terminal (FLEAT), Slotted Kinking Terminal (SKT), Manual for Assessing Safety Hardware Slotted Kinking Terminal (MSKT), X-Lite, X-Tension, and Soft Stop. For each device, the evaluation will address:

  • Crash performance in terms of vehicle occupant risk.
  • The sensitivity to varying effects such as environmental conditions, site characteristics, and impact conditions.
  • The degree of sensitivity to improper installation, maintenance and repair.

Data are being collected at test sites in four States that have agreed to participate in this pilot study: Massachusetts, Pennsylvania, California, and Missouri. This work is being done in cooperation with the National Highway Traffic Safety Administration (NHTSA), the Resource Center's Safety Technical Services Team, the Office of Safety and the division offices in each of the data collection States. The study is not collecting data across the entire State. The pilot study is only collecting data in a few State-selected regions. NOTE: Crash data collection indicates association with guardrail end terminals, not causality. 

Detailed onsite investigations are being performed for fatal and serious injury producing crashes, generally within 24 hours of receiving notification of the crash, by NHTSA's Special Crash Investigation teams. The division offices, in cooperation with their State department of transportation (DOT) partners, are collecting data for the minor and property-damage-only (PDO) crashes.

Data collection is currently scheduled to run to 2019. Based on the number of crashes expected and based on historic trends, the current timeframe for completion will likely be insufficient to collect enough data to draw statistically significant conclusions about the safety performance of the devices. However, the study will identify current challenges to conducting effective in-service performance evaluations and recommend best practices for 1) the collection of real-time data on crashes involving roadside safety hardware, 2) interagency communication at the State level regarding crash reporting, and 3) data management regarding hardware maintenance and inventory.

Data collection consists of photographs and forms. Subject matter experts can use the information from the photographs and forms for analysis. The tables below include data from the State-designed collection areas and do not reflect all guardrail and end terminal data across the entire State.

*Data collection concluded on January 25, 2019. Final reporting period through January 25, 2019.

Crash Type Distributions by State*

State Coordinating Agency Serious/Fatal PDO/
Minor
Pilot Study Start Date Full Study Start Date
California Caltrans 4 129 7/1/2016 1/25/2017
Massachusetts MassDOT 28 88 5/24/2016 5/24/2016
Missouri MoDOT 47 94 11/13/2015 11/13/2015
Pennsylvania PennDOT 9 90 2/15/2016 2/15/2016
Pennsylvania PTC 6 22 5/1/2016 5/1/2016
Totals, by Severity 94 423    
Aggregate Total 517  

Crash and End Terminal Distributions*

Crash
Type
Trinity Highway Products, LLC Road Systems, Inc. Lindsay Corporation Total
ET-
2000
ET-
Plus
Unk
ET-
Plus
4"
ET-
Plus
5"
Soft
Stop
FLEAT SKT MSKT X-
LITE
X-
Tension
Max-Tension
PDO 21 12 94 27 11 18 109 5 79 0 0 376
Minor 4 5 14 2 1 0 10 1 10 0 0 47
Serious 9 0 14 2 10 0 15 5 17 0 1 73
Fatal 0 1 8 1 0 2 4 0 5 0 0 21
Total 34 18 130 32 22 20 138 11 111 0 1 517

Note:  Serious/Fatal crashes are disaggregated as fatal until the final crash report is produced. This will account for crash-related fatalities occuring within 30 days.

Crash and End Terminal Distributions by Agency Partners*

Agency/
Partner
Trinity Highway Products, LLC Road Systems, Inc. Lindsay Corporation Total
ET-
2000
ET-
Plus
Unk
ET-
Plus
4"
ET-
Plus
5"
Soft
Stop
FLEAT SKT MSKT X-
LITE
X-
Tension
Max-Tension
Caltrans/
MAIT/SCI
0 1 1 0 0 1 0 0 1 0 0 4
Caltrans 2 0 27 8 2 9 48 1 32 0 0 129
MassDOT/
CARS
1 0 6 0 0 0 2 3 15 0 1 28
MassDOT 0 0 26 1 0 0 9 5 47 0 0 88
MoDOT/
SCI
8 0 12 2 10 0 9 2 4 0 0 47
MoDOT 12 1 38 11 10 0 15 0 7 0 0 94
PennDOT/
SCI
0 0 1 1 0 1 5 0 1 0 0 9
PennDOT 11 16 16 9 0 2 33 0 3 0 0 90
PTC/
SCI
0 0 2 0 0 0 3 0 1 0 0 6
PTC 0 0 1 0 0 7 14 0 0 0 0 22
Total 34 18 130 32 22 20 138 11 111 0 1 517

Notes: Types of data coding adjustments include the following.         

  • Reclassification of end terminals or injury severity, based upon additional documentation submitted by partners.
  • Deletion, based upon arrival of additional information, such as: subject matter experts may find that cases do not qualify because the photographed end terminal was repaired, and there is no documentation of what existed before a crash; redundant case information; or subject matter experts may find that the damaged end terminal was not an energy absorbing design and therefore not included in this study.     
  • Disqualification, based upon a non-passenger vehicle impact, such as farm vehicles and tractor trailers, for which the end terminals are neither designed nor tested.
     

Project Manager and Point of Contact

Ana Maria Eigen, D.Sc
FHWA Office of Safety Research and Development
ana.eigen@dot.gov

Updated: Friday, March 8, 2019