DG PRINT Unsealed probe shows speed caused R

An RTD light-rail train sits on the sidewalk and another section sits derailed on the tracks as crews work the scene at the intersection of East Exposition Avenue and South Sable Boulevard on Sept. 21, in Aurora.

Excessive speed and operator error caused the derailment of RTD's R-Line light rail train in September, according to investigation records recently unsealed by the Colorado Public Utilities Commission (PUC).

The R-Line train that derailed on a 90-degree curve at South Sable Boulevard and East Exposition Avenue in Aurora Sept. 21 went back in service Monday and officials have released partial details of the accident.

In its "Corrective Action Plan" filed with the PUC, RTD officials "determined the derailment resulted from excessive speed into the 10 MPH curve," but did not say what that speed was.

RTD also blamed inattention by the operator and violation of rules "by allowing the train to exceed the maximum posted track speed," and the alignment of the tracks adjacent to the street "contributed to operator inattentiveness," as did poor training and oversight.

The records did not reveal what, if any, actions were taken against the operator.

A nearly identical accident attributed to "human factors" occurred in 2019. In that accident PUC documents indicate the train entered the curve at an "excessive speed" estimated to be four times the curve's 10 mph speed limit. When the train derailed, one passenger was thrown from the car and her leg was amputated, and five others were injured.

The documents for the 2019 accident available to the public detail a number of corrective actions to be taken by RTD, which included installing eight speed-radar warning signs intended to warn drivers of excessive speed in critical areas in the light rail network, one of which was placed on a pole at the intersection where both accidents occurred.

Despite repeated requests for information from The Denver Gazette, neither the PUC nor the RTD were forthcoming about the details of the accident until Nov. 23.

As part of an investigation into the derailment and the shroud of secrecy surrounding the accident, The Denver Gazette requested access to the Corrective Action Plan filed by RTD on Nov. 4.

The PUC replied that all documents in the investigation were by statute to be kept "highly confidential" unless and until the commissioners declassified them, and that the issue of public access would be brought up at the commissioner's regular weekly meeting Nov. 23.

At that meeting the commissioners unanimously agreed to declassify the plan, but the actual investigation report is still confidential.

"Yeah, I agree as well," said PUC Commissioner John Gavan at the meeting. "Just in the first place, I never understood why these were filed as confidential documents. I think in spirit of transparency and public safety, they should be made public."

Corrective actions put in place by RTD after the 2022 derailment include lowering the 35 mph speed limit on approach to the curve to 25 mph and requiring trains to come to a stop before entering the curve.

The radar-operated speed warning sign was also moved 150 feet up the line and away from the intersection, giving operators more time to stop.

Training and supervision improvements were also required by the PUC.

The corrective action plan is now publicly available on the PUC's E-Filing System under Proceeding No. 8022I-0471R.

Comments are open to Gazette subscribers only