R Line SCADA Failures
GDT > Features > Light Rail Safety > R Line SCADA Failures
Incident Description
On Wednesday, June 14, 2023, RTD’s GM & CEO, Debra Johnson, received an email from Neil Krauss, Assistant Vice Chancellor of Initiatives and Community Engagement, University of Colorado Anschutz Medical Campus, reporting a traffic signal malfunction at East 17th Place and North Potomac Street in Aurora. Mr. Krauss noted in his email that the malfunction was related to RTD’s signaling system. He further stated the issue has become an operational, efficiency and safety concern for the University of Colorado Anschutz Medical Campus and the City of Aurora, which has resulted in traffic congestion and backups for emergency vehicles coming to the hospitals’ emergency rooms.
The incident ended up affecting five grade crossing along the R Line in Aurora at 17th Pl & Potomac, 17th Ave & Potomac, 30th & Peoria, 31st & Peoria and 33rd & Peoria. The fault was attributed to a network failure following a server migration of the R Line’s Supervisory Control and Data Acquisition (SCADA) system. This made the crossings enter “safe mode” with the gate arms being put to the down position which led to reports of drivers attempting to cross the tracks while ignoring the warnings. In addition, the electronic communication between the grade crossing and the adjacent traffic intersections was also cut, leading to the traffic signals on those intersections to enter their own “safe mode” too, which resulted in all signals flashing red and the intersection being operated as a four-way stop.
The affected portion of the R Line was required to be shut down for a few days while the issues with the SCADA system were resolved.
Jun 12th, 2023 – Multiple Issues Reported with R Line Grade Crossings
FOX31 News carries an article on the developing situation:
Jun 15th, 2023 – RTD Board Memo
“At this time, two rail crossings near the Anschutz Medical Campus remain in safe mode, whereas the remaining crossings have been restored to normal automated operation, including the crossing at 30th Avenue and Peoria Street noted in Director Ruscha’s second email. SCADA and Maintenance of Way (MOW) staff have been working diligently to restore both remaining crossings to normal operations.”
RTD, July 2023
On June 15th, 2023, RTD GM & CEO Debra Johnson advised the Board of the situation via an internal memo.
- The crossings at 30th, 31st and 33rd & Peoria are now functioning normally.
- The crossing at 17th Ave and 17th Pl remain in “safe mode” with flaggers being placed at those locations.
- From June 16th, 2023, the northernmost 3 miles of the R Line will be shut down with rail replacement buses, from 13th Avenue Station to Peoria Station.
Jun 15th, 2023 – GDT Site Visit
“Because gate arms were not functioning and a lack of roadway flaggers for drivers, several vehicles were observed crossing in front of the train with 1-2 seconds to spare. On the southbound trip this even prompted the operator to make an additional, full blast warning horn signal.”
Richard Bamber, Greater Denver Transit, June 2023
On June 15th, 2023, GDT member Richard Bamber took a ride on the R Line and found a situation similar to that described in the RTD memo above. However the safety issues of not providing highway flaggers were evident to see as we observed several “close calls” on the crossings.
Jun 21st, 2023 – The ‘R’ Line Reopens
The stretch of ”R’ Line track affected by the incident reopened on June 21st, 2023.
Jul 24th, 2023 – GDT Letter to RTD
On July 24th, 2023, GDT sent a letter to RTD requesting answers to the following questions:
- On what specific date did RTD first receive reports that the grade crossings on Peoria Street or those on 17th Place and 17th Avenue were malfunctioning?
- What factors were considered in the decision making process which resulted in the crossings being operated with the gate arms up but with no highway flaggers?
- Were the Colorado PUC advised of the situation? If so, did they formally approve a temporary operational plan or did they simply raise no objections to the temporary method of operation?.
Jul 24th, 2024 – RTD Responds to GDT
“In this instance, RTD provided flaggers to monitor and regulate train movement, not to provide traffic control for vehicles or pedestrians.”
RTD, July 2023
On July 24th, 2023, RTD issued a same day response (impressive!) to GDT’s letter. The agency did answer our three questions in full:
- On what specific date did RTD first receive reports that the grade crossings on Peoria Street or those on 17th Place and 17th Avenue were malfunctioning?
RTD Response: RTD became aware of the malfunction on Saturday, June 3, 2023. Staff was initially successful in mitigating the issue only for the malfunction to reoccur at a later date. The malfunction was finally resolved on Tuesday, June 20, 2023, and normally scheduled light rail service resumed Wednesday, June 21, 2023. - What factors were considered in the decision making process which resulted in the crossings being operated with the gate arms up but with no highway flaggers?
RTD Response: RTD does not provide traffic control and is not equipped or staffed to do so. Rather, the local police jurisdiction’s traffic division provides this service in locations where traffic signals are impacted. - Were the Colorado PUC advised of the situation? If so, did they formally approve a temporary operational plan or did they simply raise no objections to the temporary method of operation?
RTD Response: Yes, RTD informed the Colorado Public Utilities Commission (CPUC) regarding this issue and provided periodic updates. The CPUC has not communicated any safety or operational concerns regarding the agency’s response in this instance.
Jul 24th, 2024 – RTD Responds to Paolo Solorzano
“During the period when the gate crossing signal malfunction occurred, all trains were required to stop and only proceed when safe. RTD is not aware of any incidents related to train movement during the time when the gate crossings were impacted.”
RTD, July 2023
On July 24th, 2023, RTD issued a response to Paolo Solorzano, a fellow Denver based transit advocate who had contacted them with his own concerns related to “stuck down” gate arms and accidents relating to the behavior of motorists.
Our View…
Greater Denver Transit notes several issues relating to timely and accurate communication regarding these incidents:
– RTD did not formally advise the Board about the grade crossing issues until nearly two weeks after they started and after Directors had received numerous reports of problems from the public.
– RTD’s communication regarding “flaggers” was vague, leading to people to reasonably conclude that the agency was deploying highway flaggers who help motorists to avoid making mistakes, rather than railroad flaggers to assist trains that were actually placed at the affected crossings.
– The fact that the Coping Panels Project had to be suspended while the issues with the SCADA system were addressed raises questions regarding staffing levels in in RTD’s Maintenance-of-Way department.