Rendering shows the proposed FasTracks station at Sky Ridge in Lone Tree.

RTD intends to reinstate the G Line light rail, its only suburb-to-suburb rapid transit service, after it builds a 2.3-mile extension to the Southeast Corridor tracks into Lone Tree as part of the FasTracks program.

The line, which ran from Aurora’s Nine Mile Station at Parker Road and Interstate 225 south to the Lincoln Station, was eliminated earlier this year due to low ridership. But it would merit resumed service because in conjunction with the light rail extension up the Interstate 225 Corridor through Aurora, it would link the growing Fitzsimons medical campus on Colfax Avenue with the growing Douglas County area around Lone Tree and the RidgeGate area, including Sky Ridge Medical Center.

In between it would make stops at Aurora City Center, Parker Road, the Denver Tech Center, Park Meadows and the entire southeast business corridor. The operating plan is outlined in an environmental evaluation of the estimated $184.3 million Southeast Corridor Extension. That study and a companion one for the FasTracks I-225 extension indicate they would result in ridership increases of 17,600 and 17,900 per weekday, respectively.

You can read the executive summary for the Southeast Corridor Extension environmental evaluation here. The study found mostly construction-related impacts and outlines actions RTD will take to mitigate them.

The G Line would cover about 23 miles between RidgeGate and Fitzsimons. By 2035, RTD would operate trains every 15 minutes throughout the weekday.

In addition to the revived G Line, the Southeast Corridor Extension would also provide three more stations for the E and F Line trains that go to downtown Denver.

The Southeast Corridor Extension environmental evaluation was presented to the public Thursday night in the Lone Tree Recreation Center. You can view the presentation that was given at the meeting by clicking this link.

Simulation shows the proposed light rail flyover bridge over I-25 at RidgeGate in Douglas County

Starting at the current end-of-line at Lincoln Station, the double-track addition would run south around the Lincoln Avenue Interstate 25 interchange ramps and go over Lincoln on a bridge. After stopping at a new station near Sky Ridge Medical Center – a so-called “Kiss and Ride” because there would be no transit parking – the tracks would turn east and fly over I-25 to the east side into the Lone Tree City Center in the proposed RidgeGate planned development. There would be another Kiss and Ride station there as the tracks turn south, then proceed to a new end-of-line station called RidgeGate, where there would be a 1,000-car park-n-Ride facility.

You can view an interactive map of the corridor, with the capability of making geotagged comments, at this link.

Voters in Lone Tree approved joining the RTD taxing district in 2003 on the basis of plans for this extension to the T-REX project, which was then under construction.

But construction is now uncertain. That’s because the Southeast Corridor Extension is one of the seven FasTracks corridors at risk of being trimmed due to a budget gap of $2.2 billion in the program. A large spike in construction costs, right-of-way and project scope combined with the recession’s impact on RTD’s sales tax revenues have put a financial hole in the program. RTD currently estimates it would take $6.9 billion to complete the original FasTracks plan by 2017, the original schedule. When a sales tax hike for it was approved by voters in 2004, the cost was estimated at $4.7 billion.

RTD annually evaluates the entire program’s costs based on changing prices over the life of the program, and the new figure is expected to be calculated sometime in January. Because construction is spread over each year until 2017, each year’s actual results in construction cost inflation, combined with fresh projections for future inflation and tax revenues, combine to influence the bottom line. Early in the program, small changes can result in big differences down the road.

The Southeast Corridor Extension would run for 2.3 miles south from Lincoln Station to RidgeGate.