AASHTO/FHWA MEASUREMENT TASK FORCE

Allegations have been made that Trinity made changes to the dimensions of the 4-inch ET-Plus in 2012 or 2013. In addition, questions have been raised about whether the devices being retested at SwRI are fully representative of the devices actually on the roadway, To address these issues, FHWA took several steps.

First, FHWA required that the devices tested be obtained from the existing inventory of a State DOT and not specifically manufactured for testing.

Second, FHWA engineers collected measurements of approximately 1,000 ET-Plus devices on the roadways in five states, providing a statistically-valid sample to assess whether there are any significant dimensional variations in the devices installed on the roads and to confirm that the devices tested were representative of those in the field. FHWA also has obtained quality assurance/quality control manufacturing procedures and data from Trinity, which should provide additional data and insight into these issues surrounding possible dimensional variations.

To analyze all of these data and assess the representativeness of the devices tested at SwRI, FHWA formed a joint task force with AASHTO. This task force evaluated whether the devices recently crash tested are reflective of the measurements of the devices taken in the field and whether there is any evidence that there are dimensional variations in ET-Plus end terminals measured in the field that indicate there are multiple versions of the device.

The task force concluded:

• First, the devices tested in December 2014 and January 2015 are representative of the devices on the road.

• And, second, the measurements do not support allegations that Trinity manufactured a second version of the 4-inch ET-Plus.

The measurement data, task force report, and supporting information are included below.

• Report: AASHTO/FHWA Joint Task Force on ET-Plus 4" Dimensions, March 11, 2015 (PDF, 1,093 KB)

• Presentation on details of the data collection effort

• The data from the field measurements (PDF, 172 KB)

• Supporting Material

  • Joshua Harman's presentation from Jan. 2012 that presents his concerns regarding the dimensions of the ET-Plus. (PDF, 45,746 KB)
  • Joshua Harman's court documents from May 2013 that presents his allegations regarding dimensions of the ET-Plus. (PDF, 456 KB)
  • Dr. Sicking's email from Nov. 2014 that references an informal study he conducted on guide channel height dimensions (guide channel exit height (outside)) at the entrance to the extruder head. (PDF, 56 KB)
  • Dr. Sicking's deposition in Sep. 2014 where he was questioned about that informal study. (PDF, 212 KB)
  • Bloomberg News article that captures/synopsizes concerns that have been raised regarding multiple versions of the ET-Plus device. (PDF, 294 KB)
  • John Durkos' email on the dimensions of the ET-Plus. (PDF, 55 KB)
  • John Durkos' presentation on ET 2000 – ET-Plus head comparisons. (PDF, 756 KB)
  • John Durkos' presentation on alleged ET-Plus guide chute exit height (outside) dimensions. (PDF, 934 KB)
  • Brian Smith's affidavit from Feb. 2012 regarding exit gap dimensions of the ET-Plus. (PDF, 462 KB)
  • Presentation on the re-inspection of the ET-Plus device in Laurel, CA with a 1.75" exit gap. (PDF, 568 KB)
  • Three photos that were taken of the entrance to the extruder head that shows the guardrail relative to the dimension of the guide chute exit height. This was the device after crash test ET27-31 the head-on impact of the pickup truck at the guardrail height of 27 ¾". The exit gap for this test was 1.0890 and the guide chute exit height (outside) was 14.9375". (PDF, 12,714 KB)

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