HOUSTON – A federal investigation into a deadly school bus crash has revealed the Texas Department of Transportation failed to properly maintain an I-610 overpass guardrail that gave way.
On Sept. 15, 2015, a Houston Independent School District school bus that was hit by another vehicle broke through the guardrail lining the bridge above Telephone Road on I-610’s eastbound lanes.
Two students, Mariya Johnson, 17, and Janecia Chatman, 14, did not survive the accident.
The National Transportation Safety Board investigation did not list the improperly repaired guardrail as a contributing factor to the accident, but did note deficiencies in repairs and record keeping:
“TxDOT determined there had been a previous severe impact to the bridge rail in the same location as this crash. However, it could not determine when the previous impact occurred because the TxDOT districts (there are 25 districts statewide) do not keep maintenance records that document prior bridge railing improvements and repair costs. The previous impact resulted in significant damage to the concrete parapet and the anchor bolts. Evidence indicated that the bolts had been bent over by this impact, and then they were bent back and reused rather than being replaced. The previous impact also resulted in significant damage at the posts. Repair mortar had been used to patch spalls at the posts caused by the impact. The repair mortar was inferior in overall quality to the original concrete and was completely carbonated in some locations, which significantly increased the corrosion potential for the embedded steel.”
[READ: NTSB highway accident brief]
“The discovery by the NTSB that they were straightened in the repair is concerning,” Joshua Harman, an independent guardrail expert, said.
The bridge guardrail in place at the time of the school bus accident was an original 1970 design, not rated to absorb the impact of a bus at highway speed.
It is unknown whether such a guardrail, even in new condition, would have kept the bus from plunging off the bridge.
Channel 2 Investigates asked TxDOT for records regarding the bridge in question. While TxDOT did release some records regarding expenditures, the department successfully blocked the release of a large part of the open-records request because of pending litigation, including bridge-inspection reports, notes and email communications.
What is unclear is how many other TxDOT maintained overpasses may have had substandard repairs done after accidents.
TxDOT declined KPRC Channel 2 News' request for an interview:
“We have reviewed your request for a sit-down interview with TxDOT Houston District engineer Quincy Allen regarding the National Transportation Safety Board’s bus crash report. At this time, we have to respectfully decline the interview due to ongoing litigation that prevents department personnel from discussing the bus accident or the NTSB report,” Danny Perez, a public information officer, said.
The replacement overpass guardrail now in place is of a modern design, but still has the same test-level rating of TL-3, which is the same rating as the old guardrail.
“Successful tests (were run) of a 1,800 pound car impacting a barrier at an angle of 20 degrees and a 4,400 pound pickup truck impacting a barrier at an angle of 25 degrees, both at speeds of 62 mph."
The same new concrete barrier-type guardrail, had it been installed as in original design feature, common on new stretches of highway, obtains a significantly higher test rating.
“Test level 4, or TL-4, can be summarized as the successful test of a 22,000-pound single-unit truck impacting a barrier at an angle of 15 degrees, at speeds of 56 mph.”
The total weight of the HISD school bus was 16,300 pounds, according the NTSB Report.
The NTSB has asked TxDOT, moving forward, how the department plans to deal with deficiencies. The issues and responses from TxDOT are noted below.
“As a result of the crash, two issues were identified that are summarized below with a response by TxDOT in an email to NTSB investigators dated Jan. 28, 2016:
Issue No. 1: Providing direction to all TxDOT districts that the proper procedure for repairing damaged rail is to install new anchor bolts as opposed to bending back and re-using damaged bolts.
TxDOT response: TxDOT Bridge Division will include information on the Reuse of anchor bolts when repairing damaged concrete bridge rails in the next update of the Concrete Repair Manual. This manual is updated every two years. The next update of this manual is scheduled for Spring of 2017. As an interim measure, TxDOT Bridge Division will make a presentation at the next available TxDOT Directors of Maintenance meeting, hosted by the Maintenance Division. In conjunction with this meeting, directors of maintenance will be provided with materials for distribution to their employees on this issue.
Issue No. 2: Developing a maintenance record that documents bridge railing improvements and cost of repair in all TxDOT districts.
TxDOT response: TxDOT Bridge Division is currently working to deploy InspecTech software for collecting bridge inspection data. This will replace the current in-house software, Pontex.The new software is expected to be deployed by the end of calendar year 2016. After the initial roll out, TxDOT will establish procedures for making use of the capabilities for this software for collecting and documenting bridge railing improvement projects. Expected timeframe for this secondary deployment would be one year after the initial deployment. Educational materials will be developed and distributed on the requirement. This will allow TxDOT to capture bridge maintenance activities, including railing improvements and associated cost data.”