Our Next Question came in some form from a bunch of you: Pamela, Kymberly, Jay, Tracy and Sydney all asked a version of:

"#HeyNext any updates on the when the G Line will be opening?"

The short answer: there’s no opening date, but if things go well (which they obviously haven’t so far) then we could see the G line open in 3-4 months.

But that would take getting through several more steps:

The G line was supposed to open in 2016, connecting Denver Union Station to Wheat Ridge with a route through Olde Town Arvada.

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But then the A Line ran into problems with a newly-mandated technology called “positive train control,” which uses GPS location and wireless signals to operate the crossing gates where the rail line crosses roads.

Since the G Line uses the exact same system as the A Line, the Federal Railroad Administration blocked it from opening—a restriction that was recently lifted.

Here are the things that have to happen before the G line can open:


How long: “Soon.”

An administrative law judge is handling a dispute over all of this between RTD and the state Public Utilities Commission (PUC.)

The judge has already heard the evidence and the PUC expects to receive the report “soon.” The judge may make recommendations that would add additional steps to the process.


How long: 1+ months

The PUC has jurisdiction over rail lines in the state. Without its blessing, the G line can’t open—and RTD can’t do full-scale testing on the line.

A PUC spokesman told us the commissioners would likely take about a month to review the report from the judge before making a decision.

It’s also important to note that the PUC could choose to place additional requirements on RTD before allowing the line to open, potentially imposing further delays. All of this holdup comes from the same issue that required R-T-D to put human flaggers at the road crossings for the A-line. Those flaggers should be out of that job when the state P-U-C signs off.


How long: 2+ months

A spokesman for RTD told us that if it doesn’t have to comply with any further orders from PUC, the line should take about two months to test and prepare for opening day.

Trains are currently being tested on the line, but RTD still needs to conduct a full-scale test that involves running a lot more trains—a dry run of the schedule RTD plans to operate on the new rails.

G Line timeline
G Line timeline