Denver’s recent runaway growth, with high rises going up at a record pace around LoDo, is one of the main culprits in RTD’s ongoing issues with the metro area’s commuter rail network.

That revelation came in an action plan the Regional Transportation District submitted to federal regulators Friday and made public Monday. The document said Denver’s rising skyline around Union Station regularly blocks GPS signals the system relies on to keep the University of Colorado A-Line running smoothly and safely.

A software patch for that issue is coming soon, along with solutions to other factors in the crossing gate problems, according to the plan.

RTD says it is ready to open the long-delayed G-Line to Denver’s western suburbs in the first quarter of 2019 if the Federal Railroad Administration accepts its action plan. RTD officials said they are “confident that revenue operations can be performed safely” on the 11-mile line that connects Union Station to the Ward Road station in Wheat Ridge, going through the heart of Arvada along the way.

In its plan, RTD asks that the feds grant the G-Line the same waiver to operate that the University of Colorado A-Line to the airport and the B-Line to Westminster received more than two years ago. The G-Line was originally supposed to open in October 2016.

“Further delay in opening the G-Line would be an undue burden to the public and other community stakeholders,” RTD wrote to regulators in Washington, D.C.

RTD officials also asked the FRA to “expedite its review and decisions” about granting quiet zone status at crossings on all three lines, a designation that would allow trains to no longer have to blow their horns dozens of times a day.

But first, RTD acknowledged that it has work to do at the 11 at-grade crossings on the A-Line and the 16 crossings on the G-Line. The plan was submitted this weekend in reponse to the FRA’s order last month to submit a detailed action plan on how the transit agency plans to resolve the crossing-gate issues. The problem centers on a novel wireless signaling system that can keep gates in the closed position too long.

In demanding the plan, the federal agency even threatened to revoke the waiver that allows the A-Line and B-Line to operate, which could lead to the suspension of a service that currently carries more than 22,000 people a day between downtown Denver and the airport.

It is not known how long the FRA will take to review RTD’s action plan.

In the document, RTD focuses on trying to better assess how long trains stop at stations to load and off-load passengers so that a more precisely timed signal can be sent to equipment at the next crossing down the line. Hand in hand with better prediction of “dwell times” at stations, RTD said there is a need for “acceleration and deceleration smoothing to improve system prediction of arrival times at crossings.” That can be achieved through better “operator training and mentoring,” according to the plan.

RTD also spoke to the need to reduce “PTC cut outs,” which occurs when the GPS signal for positive train control is lost. Positive train control is a federally mandated rail safety system designed to eliminate derailments and other accidents on the nation’s tracks.

RTD said the number of high rises built near Union Station “has impacted reception of GPS signal in the platform area” and that it takes two minutes to reconnect with the GPS signal once the cut out occurs. RTD said in its plan to FRA that “there are a few PTC initialization issues each day due to poor reception of GPS signal.” The result: longer warning times at the York Street crossing after the train reconnects to the GPS signal at the 38th/Blake station.

The solution to the cut outs, RTD said, is coming early next year with a software upgrade provided by one of its subcontractors.

RTD told FRA regulators that it has made many adjustments to its commuter rail system over the last two-plus years in response to concerns raised but that the effort to make further improvements is “continuous.”

The metro area’s new commuter rail system carried its first passengers more than 2 1/2 years ago, when the A-Line between Union Station and Denver International Airport launched service in April 2016. The B-Line, a 6.2-mile spur to Westminster, opened a few months later.

But progress on the G-Line stalled out as problems with the timing of the A-Line’s crossing gates started becoming evident and federal regulators insisted they be fixed before any more commuter rail lines using identical signaling technology went online in the metro area.

The troubles with the gates have resulted in millions of dollars being spent on crossing-gate attendants to provide an extra layer of safety and have prevented quiet zones from being established. Noise complaints have been one of the most nettlesome issues RTD has had to confront, with trackside residents complaining that they lose sleep and are unable to enjoy dinner on their patios.

The delays have prompted a lawsuit by RTD’s private-sector contractor on the project, Denver Transit Partners, against the transit agency and RTD in return threatening to end its 34-year contract with the consortium.

Arvada Mayor Marc Williams, who has gotten an earful from city residents tired of waiting for the G-Line to open, said Monday that he’s feeling more optimistic that the metro area’s commuter rail logjam may finally break with the weekend submission of RTD’s action plan along with a letter last week from several members of Colorado’s congressional delegation urging a solution to the crossing-gate conundrum.

But he’s also wary of a process that has run into endless roadblocks.

“The proof’s going to be in the pudding,” Williams said