G Line Positive Train Control Testing Starts Thursday Night

From the grand opening celebration to the weekend station parties and art dedications, it is clear that you share our excitement about last week’s opening of the G Line! We couldn’t be more pleased to open the region’s newest mobility option for passenger service, and we hope you take advantage of the free rides available on the G Line through May 11, if you have not done so already.

We expect you know that the G Line, like all of RTD’s commuter rail lines, uses positive train control (PTC) technology to slow or stop a train if it is traveling too fast, another train is stopped ahead or a maintenance crew is working on the track. RTD and commuter rail concessionaire Denver Transit Partners (DTP) are now updating and testing PTC software on the University of Colorado A Line, the B line and the G Line as part of the Federal Railroad Administration (FRA) Grade Crossings Continuous Improvement Action Plan.

To conduct the testing, DTP has to shut down the PTC and operate with automatic train control (ATC) in place. This means that on Thursday and Friday nights from midnight to 4 a.m., trains may need to sound their horns on the G Line as they pass through the grade crossings. Horns could sound during the last few train trips each night.

DTP has planned this testing during this timeframe to minimize train horns as much as possible. While this work could affect you and your neighbors along the G Line, this plan prevents all trains from having to sound horns during other operating hours, which is a much more significant impact. If the testing is not completed by 4 a.m. Saturday, May 4, testing will be extended and monitored on a day-by-day basis.

The software update and testing is necessary for efficient and reliable operation of PTC. We apologize for the disruption and appreciate your patience as we make further improvements to this safeguard, ultimately benefiting your safety.